diff --git a/test/test_config.py b/test/test_config.py
index 6db3fcf..8de8a57 100644
--- a/test/test_config.py
+++ b/test/test_config.py
@@ -6,10 +6,11 @@
 import autopath
 from py.test import raises
 
-from tiramisu.config import Config
+from tiramisu.config import Config, SubConfig
 from tiramisu.option import IntOption, FloatOption, StrOption, ChoiceOption, \
     BoolOption, UnicodeOption, OptionDescription
 from tiramisu.error import ConflictError, ConfigError
+import weakref
 
 
 def make_description():
@@ -294,3 +295,26 @@ def test_delete_config_with_subconfig():
     raises(ConfigError, 'val[multi]')
     raises(ConfigError, 'setting[test]')
     raises(ConfigError, 'sub.make_dict()')
+
+
+def test_config_weakref():
+    o = OptionDescription('val', '', [])
+    o2 = OptionDescription('val', '', [o])
+    c = Config(o2)
+    SubConfig(o, weakref.ref(c))
+    raises(ValueError, "SubConfig(o, c)")
+    s = SubConfig(o, weakref.ref(c))
+    assert s._cfgimpl_get_context() == c
+    del(c)
+    raises(ConfigError, "s._cfgimpl_get_context()")
+
+
+def test_config_str():
+    gcdummy = BoolOption('dummy', 'dummy', default=False)
+    gcdummy1 = BoolOption('dummy1', 'dummy', default=False, properties=('disabled',))
+    o = OptionDescription('o', '', [gcdummy, gcdummy1])
+    descr = OptionDescription('tiramisu', '', [o])
+    cfg = Config(descr)
+    cfg.read_only()
+    str(cfg)
+    str(cfg.o)
diff --git a/test/test_config_api.py b/test/test_config_api.py
index f0681ea..4be9e80 100644
--- a/test/test_config_api.py
+++ b/test/test_config_api.py
@@ -4,26 +4,34 @@ from py.test import raises
 
 from tiramisu.config import Config
 from tiramisu.option import IntOption, FloatOption, StrOption, ChoiceOption, \
-    BoolOption, FilenameOption, OptionDescription
+    BoolOption, FilenameOption, UnicodeOption, SymLinkOption, IPOption, \
+    PortOption, NetworkOption, NetmaskOption, BroadcastOption, \
+    DomainnameOption, OptionDescription
+from tiramisu.error import PropertiesOptionError
 
 
 def make_description():
     gcoption = ChoiceOption('name', 'GC name', ('ref', 'framework'), 'ref')
     gcdummy = BoolOption('dummy', 'dummy', default=False)
+    prop = BoolOption('prop', '', properties=('disabled',))
+    prop2 = BoolOption('prop', '', properties=('hidden',))
     objspaceoption = ChoiceOption('objspace', 'Object space',
                                   ('std', 'thunk'), 'std')
     booloption = BoolOption('bool', 'Test boolean option', default=True)
+    booloption2 = BoolOption('bool', 'Test boolean option', default=False)
     intoption = IntOption('int', 'Test int option', default=0)
+    floatoption2 = FloatOption('float', 'Test float option', default=2.3)
     floatoption = FloatOption('float', 'Test float option', default=2.3)
     stroption = StrOption('str', 'Test string option', default="abc")
     boolop = BoolOption('boolop', 'Test boolean option op', default=True)
     wantref_option = BoolOption('wantref', 'Tests', default=False)
     wantframework_option = BoolOption('wantframework', 'Test', default=False)
-    gcgroup = OptionDescription('gc', '', [gcoption, gcdummy, floatoption])
+    gcgroup2 = OptionDescription('gc2', '', [booloption2, prop])
+    gcgroup = OptionDescription('gc', '', [gcgroup2, gcoption, gcdummy, floatoption, prop2])
     descr = OptionDescription('tiramisu', '', [gcgroup, booloption, objspaceoption,
                                                wantref_option, stroption,
                                                wantframework_option,
-                                               intoption, boolop])
+                                               intoption, boolop, floatoption2])
     return descr
 
 
@@ -62,6 +70,17 @@ def test_iter_config():
         [('string', 'string'), ('string2', 'string2')]
 
 
+def test_iter_config_property():
+    "iteration on config object"
+    s = StrOption("string", "", default="string", properties=('disabled',))
+    s2 = StrOption("string2", "", default="string2")
+    descr = OptionDescription("options", "", [s, s2])
+    config = Config(descr)
+    config.read_only()
+    assert [(name, value) for name, value in config] == \
+        [('string2', 'string2')]
+
+
 def test_iter_subconfig():
     "iteration on config sub object"
     descr = make_description()
@@ -100,20 +119,41 @@ def test_find_in_config():
     "finds option in config"
     descr = make_description()
     conf = Config(descr)
+    conf.read_only()
     assert conf.find(byname='dummy') == [conf.unwrap_from_path('gc.dummy')]
+    assert conf.find(byname='float') == [conf.unwrap_from_path('gc.float'), conf.unwrap_from_path('float')]
+    assert conf.find_first(byname='bool') == conf.unwrap_from_path('gc.gc2.bool')
+    assert conf.find_first(byname='bool', byvalue=True) == conf.unwrap_from_path('bool')
     assert conf.find_first(byname='dummy') == conf.unwrap_from_path('gc.dummy')
+    assert conf.find_first(byname='float') == conf.unwrap_from_path('gc.float')
     assert conf.find(bytype=ChoiceOption) == [conf.unwrap_from_path('gc.name'), conf.unwrap_from_path('objspace')]
     assert conf.find_first(bytype=ChoiceOption) == conf.unwrap_from_path('gc.name')
     assert conf.find(byvalue='ref') == [conf.unwrap_from_path('gc.name')]
     assert conf.find_first(byvalue='ref') == conf.unwrap_from_path('gc.name')
+    assert conf.find(byname='prop') == [conf.unwrap_from_path('gc.prop')]
+    conf.read_write()
+    raises(AttributeError, "assert conf.find(byname='prop')")
+    assert conf.find(byname='prop', check_properties=False) == [conf.unwrap_from_path('gc.gc2.prop'), conf.unwrap_from_path('gc.prop')]
+    #assert conf.find_first(byname='prop') == conf.unwrap_from_path('gc.prop')
     # combinaison of filters
     assert conf.find(bytype=BoolOption, byname='dummy') == [conf.unwrap_from_path('gc.dummy')]
     assert conf.find_first(bytype=BoolOption, byname='dummy') == conf.unwrap_from_path('gc.dummy')
     assert conf.find(byvalue=False, byname='dummy') == [conf.unwrap_from_path('gc.dummy')]
     assert conf.find_first(byvalue=False, byname='dummy') == conf.unwrap_from_path('gc.dummy')
-    ## byattrs
-    #assert conf.find_first(byattrs= dict(default=2.3)) == conf.unwrap_from_path('gc.float')
-    #assert conf.find_first(byvalue=False, byname='dummy', byattrs=dict(default=False)) == conf.unwrap_from_path('gc.dummy')
+    #subconfig
+    assert conf.gc.find(byname='dummy') == [conf.unwrap_from_path('gc.dummy')]
+    assert conf.gc.find(byname='float') == [conf.unwrap_from_path('gc.float')]
+    assert conf.gc.find(byname='bool') == [conf.unwrap_from_path('gc.gc2.bool')]
+    assert conf.gc.find_first(byname='bool', byvalue=False) == conf.unwrap_from_path('gc.gc2.bool')
+    raises(AttributeError, "assert conf.gc.find_first(byname='bool', byvalue=True)")
+    raises(AttributeError, "conf.gc.find(byname='wantref').first()")
+    assert conf.gc.find(byname='prop', check_properties=False) == [conf.unwrap_from_path('gc.gc2.prop'), conf.unwrap_from_path('gc.prop')]
+    conf.read_only()
+    assert conf.gc.find(byname='prop') == [conf.unwrap_from_path('gc.prop')]
+    # not OptionDescription
+    raises(AttributeError, "conf.find_first(byname='gc')")
+    raises(AttributeError, "conf.gc.find_first(byname='gc2')")
+    raises(ValueError, "conf.find(byname='bool', type_='unknown')")
 
 
 def test_find_multi():
@@ -152,3 +192,66 @@ def test_filename():
     c.a = u'tmp/text.txt'
     raises(ValueError, "c.a = u'/tmp/with space.txt'")
     raises(ValueError, "c.a = u'/tmp/with$.txt'")
+
+
+def test_iter_all():
+    s = StrOption("string", "", default="string")
+    s2 = StrOption("string2", "", default="string2")
+    descr = OptionDescription("options", "", [s, s2])
+    config = Config(descr)
+    assert list(config.iter_all()) == [('string', 'string'), ('string2', 'string2')]
+    for i in config.iter_all():
+        #test StopIteration
+        break
+
+
+def test_iter_all_prop():
+    s = StrOption("string", "", default="string", properties=('disabled',))
+    s2 = StrOption("string2", "", default="string2")
+    descr = OptionDescription("options", "", [s, s2])
+    config = Config(descr)
+    config.read_only()
+    assert list(config.iter_all()) == [('string2', 'string2')]
+
+
+def test_impl_getpaths():
+    s = StrOption("string", "", default="string", properties=('disabled',))
+    s2 = StrOption("string2", "", default="string2")
+    s3 = StrOption("string3", "", default="string3")
+    s4 = StrOption("string4", "", default="string4", properties=('hidden',))
+    od = OptionDescription('od', '', [s3, s4])
+    descr = OptionDescription("options", "", [s, s2, od])
+    config = Config(descr)
+    assert ['string', 'string2', 'od.string3', 'od.string4'] == config.cfgimpl_get_description().impl_getpaths()
+    assert ['string', 'string2', 'od', 'od.string3', 'od.string4'] == config.cfgimpl_get_description().impl_getpaths(include_groups=True)
+    config.read_write()
+    raises(PropertiesOptionError, "config.od.string4")
+    assert ['string', 'string2', 'od.string3', 'od.string4'] == config.cfgimpl_get_description().impl_getpaths()
+    assert ['string', 'string2', 'od', 'od.string3', 'od.string4'] == config.cfgimpl_get_description().impl_getpaths(include_groups=True)
+
+
+def test_invalid_option():
+    raises(TypeError, "ChoiceOption('a', '', [1, 2])")
+    raises(TypeError, "ChoiceOption('a', '', 1)")
+    raises(TypeError, "ChoiceOption('a', '', (1,), open_values='string')")
+    raises(ValueError, "ChoiceOption('a', '', (1,), 3)")
+    raises(ValueError, "FloatOption('a', '', 'string')")
+    raises(ValueError, "UnicodeOption('a', '', 1)")
+    raises(ValueError, "SymLinkOption('a', 'string')")
+    raises(ValueError, "IPOption('a', '', 1)")
+    raises(ValueError, "IPOption('a', '', 'string')")
+    raises(ValueError, "PortOption('a', '', 'string')")
+    raises(ValueError, "PortOption('a', '', '11:12:13', allow_range=True)")
+    raises(ValueError, "PortOption('a', '', 11111111111111111111)")
+    raises(ValueError, "PortOption('a', '', allow_zero=True, allow_wellknown=False, allow_registred=True, allow_private=False)")
+    raises(ValueError, "PortOption('a', '', allow_zero=True, allow_wellknown=True, allow_registred=False, allow_private=True)")
+    raises(ValueError, "PortOption('a', '', allow_zero=True, allow_wellknown=False, allow_registred=False, allow_private=True)")
+    raises(ValueError, "PortOption('a', '', allow_zero=True, allow_wellknown=False, allow_registred=True, allow_private=True)")
+    raises(ValueError, "PortOption('a', '', allow_zero=False, allow_wellknown=False, allow_registred=False, allow_private=False)")
+    raises(ValueError, "NetworkOption('a', '', 'string')")
+    raises(ValueError, "NetmaskOption('a', '', 'string')")
+    raises(ValueError, "BroadcastOption('a', '', 'string')")
+    raises(ValueError, "DomainnameOption('a', '', 'string')")
+    raises(ValueError, "DomainnameOption('a', '', type_='string')")
+    raises(ValueError, "DomainnameOption('a', '', allow_ip='string')")
+    raises(ValueError, "DomainnameOption('a', '', allow_without_dot='string')")
diff --git a/test/test_config_domain.py b/test/test_config_domain.py
index 9fd9ed3..bcae92a 100644
--- a/test/test_config_domain.py
+++ b/test/test_config_domain.py
@@ -7,9 +7,9 @@ from tiramisu.option import DomainnameOption, EmailOption, URLOption, OptionDesc
 
 def test_domainname():
     d = DomainnameOption('d', '')
-    e = DomainnameOption('e', '', "toto.com")
     f = DomainnameOption('f', '', allow_without_dot=True)
-    od = OptionDescription('a', '', [d, f])
+    g = DomainnameOption('g', '', allow_ip=True)
+    od = OptionDescription('a', '', [d, f, g])
     c = Config(od)
     c.read_write()
     c.d = 'toto.com'
@@ -24,6 +24,12 @@ def test_domainname():
     #
     c.f = 'toto.com'
     c.f = 'toto'
+    raises(ValueError, "c.f = 'domainnametoolongthathavemorethanmaximumsizeforatruedomainnameanditsnoteasytogeneratesolongdomainnamewithoutrepeatdomainnametoolongthathavemorethanmaximumsizeforatruedomainnameanditsnoteasytogeneratesolongdomainnamewithoutrepeatbutimnotabletodoitnowiendityeah'")
+    raises(ValueError, "c.f = 'd'")
+    #
+    c.g = 'toto.com'
+    c.g = '192.168.1.0'
+    c.g = '192.168.1.29'
 
 def test_special_domain_name():
     """domain name option that starts with a number or not
@@ -69,6 +75,7 @@ def test_email():
     c.e = 'root@foo.com'
     raises(ValueError, "c.e = 'root'")
     raises(ValueError, "c.e = 'root@domain'")
+    raises(ValueError, "c.e = 'root[]@domain'")
 
 
 def test_url():
@@ -89,3 +96,4 @@ def test_url():
     c.u = 'https://foo.com:8443'
     c.u = 'https://foo.com:8443/'
     c.u = 'https://foo.com:8443/index.html'
+    raises(ValueError, "c.u = 'https://foo.com:84438989'")
diff --git a/test/test_dereference.py b/test/test_dereference.py
index be8dfde..358c1b9 100644
--- a/test/test_dereference.py
+++ b/test/test_dereference.py
@@ -2,8 +2,8 @@
 import autopath
 #from py.test import raises
 
-from tiramisu.config import Config
-from tiramisu.option import BoolOption, OptionDescription
+from tiramisu.config import Config, GroupConfig, MetaConfig
+from tiramisu.option import BoolOption, IntOption, OptionDescription
 import weakref
 
 
@@ -109,3 +109,31 @@ def test_deref_optiondescription_config():
     assert w() is not None
     del(c)
     assert w() is None
+
+
+def test_deref_groupconfig():
+    i1 = IntOption('i1', '')
+    od1 = OptionDescription('od1', '', [i1])
+    od2 = OptionDescription('od2', '', [od1])
+    conf1 = Config(od2)
+    conf2 = Config(od2)
+    meta = GroupConfig([conf1, conf2])
+    w = weakref.ref(conf1)
+    del(conf1)
+    assert w() is not None
+    del(meta)
+    assert w() is None
+
+
+def test_deref_metaconfig():
+    i1 = IntOption('i1', '')
+    od1 = OptionDescription('od1', '', [i1])
+    od2 = OptionDescription('od2', '', [od1])
+    conf1 = Config(od2)
+    conf2 = Config(od2)
+    meta = MetaConfig([conf1, conf2])
+    w = weakref.ref(conf1)
+    del(conf1)
+    assert w() is not None
+    del(meta)
+    assert w() is None
diff --git a/test/test_metaconfig.py b/test/test_metaconfig.py
index 35d65d5..a8fc395 100644
--- a/test/test_metaconfig.py
+++ b/test/test_metaconfig.py
@@ -1,172 +1,203 @@
-#import autopath
+import autopath
 
-#from py.test import raises
+from py.test import raises
 
-#from tiramisu.setting import owners
-#from tiramisu.config import Config, MetaConfig
-#from tiramisu.option import IntOption, OptionDescription
-#from tiramisu.error import ConfigError
+from tiramisu.setting import owners
+from tiramisu.config import Config, GroupConfig, MetaConfig
+from tiramisu.option import IntOption, OptionDescription
+from tiramisu.error import ConfigError, PropertiesOptionError
 
-#owners.addowner('meta')
+owners.addowner('meta')
 
 
-#def make_description():
-#    i1 = IntOption('i1', '')
-#    i2 = IntOption('i2', '', default=1)
-#    i3 = IntOption('i3', '')
-#    i4 = IntOption('i4', '', default=2)
-#    od1 = OptionDescription('od1', '', [i1, i2, i3, i4])
-#    od2 = OptionDescription('od2', '', [od1])
-#    conf1 = Config(od2)
-#    conf2 = Config(od2)
-#    meta = MetaConfig([conf1, conf2])
-#    meta.cfgimpl_get_settings().setowner(owners.meta)
-#    return meta
+def make_description():
+    i1 = IntOption('i1', '')
+    i2 = IntOption('i2', '', default=1)
+    i3 = IntOption('i3', '')
+    i4 = IntOption('i4', '', default=2)
+    i5 = IntOption('i5', '', default=[2], multi=True)
+    i6 = IntOption('i6', '', properties=('disabled',))
+    od1 = OptionDescription('od1', '', [i1, i2, i3, i4, i5, i6])
+    od2 = OptionDescription('od2', '', [od1])
+    conf1 = Config(od2)
+    conf2 = Config(od2)
+    conf1.read_write()
+    conf2.read_write()
+    meta = MetaConfig([conf1, conf2])
+    meta.cfgimpl_get_settings().setowner(owners.meta)
+    return meta
 
 
-##FIXME ne pas mettre 2 meta dans une config
-##FIXME ne pas mettre 2 OD differents dans un meta
-#def test_none():
-#    meta = make_description()
-#    conf1, conf2 = meta._impl_children
-#    assert conf1.od1.i3 is conf2.od1.i3 is None
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i3')) is conf2.getowner(conf2.unwrap_from_path('od1.i3')) is owners.default
-#    meta.od1.i3 = 3
-#    assert conf1.od1.i3 == conf2.od1.i3 == 3
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i3')) is conf2.getowner(conf2.unwrap_from_path('od1.i3')) is owners.meta
-#    meta.od1.i3 = 3
-#    conf1.od1.i3 = 2
-#    assert conf1.od1.i3 == 2
-#    assert conf2.od1.i3 == 3
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i3')) is owners.user
-#    assert conf2.getowner(conf2.unwrap_from_path('od1.i3')) is owners.meta
-#    meta.od1.i3 = 4
-#    assert conf1.od1.i3 == 2
-#    assert conf2.od1.i3 == 4
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i3')) is owners.user
-#    assert conf2.getowner(conf2.unwrap_from_path('od1.i3')) is owners.meta
-#    del(meta.od1.i3)
-#    assert conf1.od1.i3 == 2
-#    assert conf2.od1.i3 is None
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i3')) is owners.user
-#    assert conf2.getowner(conf2.unwrap_from_path('od1.i3')) is owners.default
-#    del(conf1.od1.i3)
-#    assert conf1.od1.i3 is conf2.od1.i3 is None
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i3')) is conf2.getowner(conf2.unwrap_from_path('od1.i3')) is owners.default
+#FIXME ne pas mettre 2 meta dans une config
+#FIXME ne pas mettre 2 OD differents dans un meta
+#FIXME serialization
+def test_none():
+    meta = make_description()
+    conf1, conf2 = meta.cfgimpl_get_children()
+    assert conf1.od1.i3 is conf2.od1.i3 is None
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i3')) is conf2.getowner(conf2.unwrap_from_path('od1.i3')) is owners.default
+    meta.od1.i3 = 3
+    assert conf1.od1.i3 == conf2.od1.i3 == 3
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i3')) is conf2.getowner(conf2.unwrap_from_path('od1.i3')) is owners.meta
+    meta.od1.i3 = 3
+    conf1.od1.i3 = 2
+    assert conf1.od1.i3 == 2
+    assert conf2.od1.i3 == 3
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i3')) is owners.user
+    assert conf2.getowner(conf2.unwrap_from_path('od1.i3')) is owners.meta
+    meta.od1.i3 = 4
+    assert conf1.od1.i3 == 2
+    assert conf2.od1.i3 == 4
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i3')) is owners.user
+    assert conf2.getowner(conf2.unwrap_from_path('od1.i3')) is owners.meta
+    del(meta.od1.i3)
+    assert conf1.od1.i3 == 2
+    assert conf2.od1.i3 is None
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i3')) is owners.user
+    assert conf2.getowner(conf2.unwrap_from_path('od1.i3')) is owners.default
+    del(conf1.od1.i3)
+    assert conf1.od1.i3 is conf2.od1.i3 is None
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i3')) is conf2.getowner(conf2.unwrap_from_path('od1.i3')) is owners.default
 
 
-#def test_default():
-#    meta = make_description()
-#    conf1, conf2 = meta._impl_children
-#    assert conf1.od1.i2 == conf2.od1.i2 == 1
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.default
-#    meta.od1.i2 = 3
-#    assert conf1.od1.i2 == conf2.od1.i2 == 3
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.meta
-#    meta.od1.i2 = 3
-#    conf1.od1.i2 = 2
-#    assert conf1.od1.i2 == 2
-#    assert conf2.od1.i2 == 3
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is owners.user
-#    assert conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.meta
-#    meta.od1.i2 = 4
-#    assert conf1.od1.i2 == 2
-#    assert conf2.od1.i2 == 4
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is owners.user
-#    assert conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.meta
-#    del(meta.od1.i2)
-#    assert conf1.od1.i2 == 2
-#    assert conf2.od1.i2 == 1
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is owners.user
-#    assert conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.default
-#    del(conf1.od1.i2)
-#    assert conf1.od1.i2 == conf2.od1.i2 == 1
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.default
+def test_default():
+    meta = make_description()
+    conf1, conf2 = meta.cfgimpl_get_children()
+    assert conf1.od1.i2 == conf2.od1.i2 == 1
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.default
+    meta.od1.i2 = 3
+    assert conf1.od1.i2 == conf2.od1.i2 == 3
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.meta
+    meta.od1.i2 = 3
+    conf1.od1.i2 = 2
+    assert conf1.od1.i2 == 2
+    assert conf2.od1.i2 == 3
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is owners.user
+    assert conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.meta
+    meta.od1.i2 = 4
+    assert conf1.od1.i2 == 2
+    assert conf2.od1.i2 == 4
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is owners.user
+    assert conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.meta
+    del(meta.od1.i2)
+    assert conf1.od1.i2 == 2
+    assert conf2.od1.i2 == 1
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is owners.user
+    assert conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.default
+    del(conf1.od1.i2)
+    assert conf1.od1.i2 == conf2.od1.i2 == 1
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.default
 
 
-#def test_contexts():
-#    meta = make_description()
-#    conf1, conf2 = meta._impl_children
-#    assert conf1.od1.i2 == conf2.od1.i2 == 1
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.default
-#    meta.set_contexts('od1.i2', 6)
-#    assert meta.od1.i2 == 1
-#    assert conf1.od1.i2 == conf2.od1.i2 == 6
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.user
+def test_contexts():
+    meta = make_description()
+    conf1, conf2 = meta.cfgimpl_get_children()
+    assert conf1.od1.i2 == conf2.od1.i2 == 1
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.default
+    meta.setattrs('od1.i2', 6)
+    assert meta.od1.i2 == 1
+    assert conf1.od1.i2 == conf2.od1.i2 == 6
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.user
 
 
-#def test_find():
-#    meta = make_description()
-#    i2 = meta.unwrap_from_path('od1.i2')
-#    assert [i2] == meta.find(byname='i2')
-#    assert i2 == meta.find_first(byname='i2')
-#    assert meta.make_dict() == {'od1.i4': 2, 'od1.i1': None, 'od1.i3': None, 'od1.i2': 1}
+def test_find():
+    meta = make_description()
+    i2 = meta.unwrap_from_path('od1.i2')
+    assert [i2] == meta.find(byname='i2')
+    assert i2 == meta.find_first(byname='i2')
+    assert meta.make_dict() == {'od1.i4': 2, 'od1.i1': None, 'od1.i3': None,
+                                'od1.i2': 1, 'od1.i5': [2], 'od1.i6': None}
 
 
-#def test_meta_meta():
-#    meta1 = make_description()
-#    meta2 = MetaConfig([meta1])
-#    meta2.cfgimpl_get_settings().setowner(owners.meta)
-#    conf1, conf2 = meta1._impl_children
-#    assert conf1.od1.i2 == conf2.od1.i2 == 1
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.default
-#    meta2.od1.i2 = 3
-#    assert conf1.od1.i2 == conf2.od1.i2 == 3
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.meta
-#    meta2.od1.i2 = 3
-#    conf1.od1.i2 = 2
-#    assert conf1.od1.i2 == 2
-#    assert conf2.od1.i2 == 3
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is owners.user
-#    assert conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.meta
-#    meta2.od1.i2 = 4
-#    assert conf1.od1.i2 == 2
-#    assert conf2.od1.i2 == 4
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is owners.user
-#    assert conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.meta
-#    del(meta2.od1.i2)
-#    assert conf1.od1.i2 == 2
-#    assert conf2.od1.i2 == 1
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is owners.user
-#    assert conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.default
-#    del(conf1.od1.i2)
-#    assert conf1.od1.i2 == conf2.od1.i2 == 1
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.default
-#    meta1.od1.i2 = 6
-#    assert conf1.od1.i2 == conf2.od1.i2 == 6
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.meta
+def test_meta_meta():
+    meta1 = make_description()
+    meta2 = MetaConfig([meta1])
+    meta2.cfgimpl_get_settings().setowner(owners.meta)
+    conf1, conf2 = meta1.cfgimpl_get_children()
+    assert conf1.od1.i2 == conf2.od1.i2 == 1
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.default
+    meta2.od1.i2 = 3
+    assert conf1.od1.i2 == conf2.od1.i2 == 3
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.meta
+    meta2.od1.i2 = 3
+    conf1.od1.i2 = 2
+    assert conf1.od1.i2 == 2
+    assert conf2.od1.i2 == 3
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is owners.user
+    assert conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.meta
+    meta2.od1.i2 = 4
+    assert conf1.od1.i2 == 2
+    assert conf2.od1.i2 == 4
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is owners.user
+    assert conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.meta
+    del(meta2.od1.i2)
+    assert conf1.od1.i2 == 2
+    assert conf2.od1.i2 == 1
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is owners.user
+    assert conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.default
+    del(conf1.od1.i2)
+    assert conf1.od1.i2 == conf2.od1.i2 == 1
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.default
+    meta1.od1.i2 = 6
+    assert conf1.od1.i2 == conf2.od1.i2 == 6
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i2')) is conf2.getowner(conf2.unwrap_from_path('od1.i2')) is owners.meta
 
 
-#def test_meta_meta_set():
-#    meta1 = make_description()
-#    meta2 = MetaConfig([meta1])
-#    meta2.cfgimpl_get_settings().setowner(owners.meta)
-#    conf1, conf2 = meta1._impl_children
-#    meta2.set_contexts('od1.i1', 7)
-#    assert conf1.od1.i1 == conf2.od1.i1 == 7
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i1')) is conf2.getowner(conf2.unwrap_from_path('od1.i1')) is owners.user
-#    assert [conf1, conf2] == meta2.find_first_contexts(byname='i1', byvalue=7)
-#    conf1.od1.i1 = 8
-#    assert [conf2] == meta2.find_first_contexts(byname='i1', byvalue=7)
-#    assert [conf1] == meta2.find_first_contexts(byname='i1', byvalue=8)
-#    raises(AttributeError, "meta2.find_first_contexts(byname='i1', byvalue=10)")
+def test_meta_meta_set():
+    meta1 = make_description()
+    meta2 = MetaConfig([meta1])
+    meta2.cfgimpl_get_settings().setowner(owners.meta)
+    conf1, conf2 = meta1.cfgimpl_get_children()
+    meta2.setattrs('od1.i1', 7)
+    #PropertiesOptionError
+    meta2.setattrs('od1.i6', 7)
+    assert conf1.od1.i1 == conf2.od1.i1 == 7
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i1')) is conf2.getowner(conf2.unwrap_from_path('od1.i1')) is owners.user
+    assert [conf1, conf2] == meta2.find_firsts(byname='i1', byvalue=7)
+    conf1.od1.i1 = 8
+    assert [conf1, conf2] == meta2.find_firsts(byname='i1')
+    assert [conf2] == meta2.find_firsts(byname='i1', byvalue=7)
+    assert [conf1] == meta2.find_firsts(byname='i1', byvalue=8)
+    assert [conf1, conf2] == meta2.find_firsts(byname='i5', byvalue=2)
+    raises(AttributeError, "meta2.find_firsts(byname='i1', byvalue=10)")
+    raises(AttributeError, "meta2.find_firsts(byname='not', byvalue=10)")
+    raises(AttributeError, "meta2.find_firsts(byname='i6')")
 
 
-#def test_not_meta():
-#    i1 = IntOption('i1', '')
-#    od1 = OptionDescription('od1', '', [i1])
-#    od2 = OptionDescription('od2', '', [od1])
-#    conf1 = Config(od2)
-#    conf2 = Config(od2)
-#    meta = MetaConfig([conf1, conf2], False)
-#    raises(ConfigError, 'meta.od1.i1')
-#    conf1, conf2 = meta._impl_children
-#    meta.set_contexts('od1.i1', 7)
-#    assert conf1.od1.i1 == conf2.od1.i1 == 7
-#    assert conf1.getowner(conf1.unwrap_from_path('od1.i1')) is conf2.getowner(conf2.unwrap_from_path('od1.i1')) is owners.user
+def test_not_meta():
+    i1 = IntOption('i1', '')
+    od1 = OptionDescription('od1', '', [i1])
+    od2 = OptionDescription('od2', '', [od1])
+    conf1 = Config(od2)
+    conf2 = Config(od2)
+    raises(ValueError, "GroupConfig(conf1)")
+    meta = GroupConfig([conf1, conf2])
+    raises(ConfigError, 'meta.od1.i1')
+    conf1, conf2 = meta.cfgimpl_get_children()
+    meta.setattrs('od1.i1', 7)
+    assert conf1.od1.i1 == conf2.od1.i1 == 7
+    assert conf1.getowner(conf1.unwrap_from_path('od1.i1')) is conf2.getowner(conf2.unwrap_from_path('od1.i1')) is owners.user
 
 
-#def test_meta_path():
-#    meta = make_description()
-#    assert meta._impl_path is None
-#    assert meta.od1._impl_path == 'od1'
+def test_meta_path():
+    meta = make_description()
+    assert meta._impl_path is None
+    assert meta.od1._impl_path == 'od1'
+
+
+def test_meta_unconsistent():
+    i1 = IntOption('i1', '')
+    i2 = IntOption('i2', '', default=1)
+    i3 = IntOption('i3', '')
+    i4 = IntOption('i4', '', default=2)
+    od1 = OptionDescription('od1', '', [i1, i2, i3, i4])
+    od2 = OptionDescription('od2', '', [od1])
+    conf1 = Config(od2)
+    conf2 = Config(od2)
+    conf3 = Config(od2)
+    conf4 = Config(od1)
+    meta = MetaConfig([conf1, conf2])
+    meta.cfgimpl_get_settings().setowner(owners.meta)
+    raises(TypeError, 'MetaConfig("string")')
+    raises(ValueError, "MetaConfig([conf1, conf3])")
+    raises(ValueError, "MetaConfig([conf3, conf4])")
diff --git a/test/test_multi.py b/test/test_multi.py
new file mode 100644
index 0000000..42fd8e1
--- /dev/null
+++ b/test/test_multi.py
@@ -0,0 +1,21 @@
+# coding: utf-8
+import autopath
+from tiramisu.value import Multi
+from tiramisu.option import IntOption, OptionDescription
+from tiramisu.config import Config
+from tiramisu.error import ConfigError
+
+import weakref
+from py.test import raises
+
+
+def test_multi():
+    i = IntOption('int', '', multi=True)
+    o = OptionDescription('od', '', [i])
+    c = Config(o)
+    multi = Multi([1,2,3], weakref.ref(c), i, 'int')
+    raises(ValueError, "Multi([1,2,3], c, i, 'int')")
+    raises(ValueError, "Multi(multi, weakref.ref(c), i, 'int')")
+    assert c is multi._getcontext()
+    del(c)
+    raises(ConfigError, "multi._getcontext()")
diff --git a/test/test_option_calculation.py b/test/test_option_calculation.py
index 91d61a4..89f9291 100644
--- a/test/test_option_calculation.py
+++ b/test/test_option_calculation.py
@@ -373,6 +373,9 @@ def test_callback_multi_value():
     assert cfg.val2 == ['val']
     assert cfg.val3 == ['yes']
     assert cfg.val4 == ['val', 'yes']
+    cfg.val2.append('new')
+    assert cfg.val1 == ['val']
+    assert cfg.val2 == ['val', 'new']
 
 
 def test_callback_multi_list():
@@ -466,6 +469,66 @@ def test_callback_master_and_slaves_slave():
     assert cfg.val1.val2 == ['val2', 'val2', 'val']
 
 
+def test_callback_master_and_slaves_slave_cal():
+    val3 = StrOption('val3', "", multi=True)
+    val1 = StrOption('val1', "", multi=True, callback=return_value, callback_params={'': ((val3, False),)})
+    val2 = StrOption('val2', "", multi=True, callback=return_val)
+    interface1 = OptionDescription('val1', '', [val1, val2])
+    interface1.impl_set_group_type(groups.master)
+    maconfig = OptionDescription('rootconfig', '', [interface1, val3])
+    cfg = Config(maconfig)
+    cfg.read_write()
+    assert cfg.val3 == []
+    assert cfg.val1.val1 == []
+    assert cfg.val1.val2 == []
+    cfg.val1.val1 = ['val1']
+    cfg.val3 = ['val1']
+    assert cfg.val1.val1 == ['val1']
+    assert cfg.val1.val2 == ['val']
+    assert cfg.val1.val1 == ['val1']
+    assert cfg.val1.val2 == ['val']
+    del(cfg.val1.val1)
+    cfg.val1.val2 = ['val']
+    cfg.val3 = ['val1', 'val2']
+    assert cfg.val1.val2 == ['val', 'val']
+    assert cfg.val1.val1 == ['val1', 'val2']
+    cfg.val1.val2 = ['val1', 'val2']
+    cfg.val3.pop(1)
+    # cannot remove slave's value because master is calculated
+    # so raise
+    raises(SlaveError, "cfg.val1.val1")
+    raises(SlaveError, "cfg.val1.val2")
+    cfg.val3 = ['val1', 'val2', 'val3']
+    assert cfg.val1.val2 == ['val1', 'val2', 'val']
+
+
+def test_callback_master_and_slaves_slave_cal2():
+    val3 = StrOption('val3', "", ['val', 'val'], multi=True)
+    val1 = StrOption('val1', "", multi=True, callback=return_value, callback_params={'': ((val3, False),)})
+    val2 = StrOption('val2', "", ['val2', 'val2'], multi=True)
+    interface1 = OptionDescription('val1', '', [val1, val2])
+    interface1.impl_set_group_type(groups.master)
+    maconfig = OptionDescription('rootconfig', '', [interface1, val3])
+    cfg = Config(maconfig)
+    cfg.read_write()
+    assert cfg.val3 == ['val', 'val']
+    assert cfg.val1.val1 == ['val', 'val']
+    assert cfg.val1.val2 == ['val2', 'val2']
+    cfg.val3.pop(1)
+#    # cannot remove slave's value because master is calculated
+#    # so raise
+    raises(SlaveError, "cfg.val1.val1")
+    raises(SlaveError, "cfg.val1.val2")
+    cfg.val3 = ['val', 'val']
+    assert cfg.val3 == ['val', 'val']
+    assert cfg.val1.val1 == ['val', 'val']
+    assert cfg.val1.val2 == ['val2', 'val2']
+    raises(SlaveError, "cfg.val1.val1 = ['val']")
+    assert cfg.val3 == ['val', 'val']
+    assert cfg.val1.val1 == ['val', 'val']
+    assert cfg.val1.val2 == ['val2', 'val2']
+
+
 def test_callback_master_and_slaves_slave_list():
     val1 = StrOption('val1', "", multi=True)
     val2 = StrOption('val2', "", multi=True, callback=return_list)
diff --git a/test/test_option_consistency.py b/test/test_option_consistency.py
index a7ff41c..1beb4bb 100644
--- a/test/test_option_consistency.py
+++ b/test/test_option_consistency.py
@@ -169,6 +169,18 @@ def test_consistency_network_netmask():
     raises(ValueError, "c.a = '192.168.1.1'")
 
 
+def test_consistency_ip_netmask_network_error():
+    a = IPOption('a', '')
+    b = NetworkOption('b', '')
+    c = NetmaskOption('c', '')
+    od = OptionDescription('od', '', [a, b, c])
+    c.impl_add_consistency('ip_netmask', a, b)
+    c = Config(od)
+    c.a = '192.168.1.1'
+    c.b = '192.168.1.0'
+    raises(ConfigError, "c.c = '255.255.255.0'")
+
+
 def test_consistency_ip_netmask_error_multi():
     a = IPOption('a', '', multi=True)
     b = NetmaskOption('b', '')
@@ -217,6 +229,8 @@ def test_consistency_ip_netmask_multi_master():
     c.b = ['255.255.255.255']
     c.b = ['255.255.255.0']
     raises(ValueError, "c.a = ['192.168.1.0']")
+    c.a = ['192.168.1.128']
+    raises(ValueError, "c.b = ['255.255.255.128']")
     c.a = ['192.168.1.2', '192.168.1.3']
 
 
@@ -260,6 +274,20 @@ def test_consistency_broadcast():
     c.c[1] = '192.168.2.255'
 
 
+def test_consistency_broadcast_error():
+    a = NetworkOption('a', '', multi=True)
+    b = NetmaskOption('b', '', multi=True)
+    c = BroadcastOption('c', '', multi=True)
+    od = OptionDescription('a', '', [a, b, c])
+    od.impl_set_group_type(groups.master)
+    b.impl_add_consistency('network_netmask', a)
+    c.impl_add_consistency('broadcast', a)
+    c = Config(od)
+    c.a = ['192.168.1.0']
+    c.b = ['255.255.255.0']
+    raises(ConfigError, "c.c = ['192.168.1.255']")
+
+
 def test_consistency_broadcast_default():
     a = NetworkOption('a', '', '192.168.1.0')
     b = NetmaskOption('b', '', '255.255.255.128')
diff --git a/test/test_option_owner.py b/test/test_option_owner.py
index b758e91..d4c3f6b 100644
--- a/test/test_option_owner.py
+++ b/test/test_option_owner.py
@@ -36,6 +36,7 @@ def test_default_owner():
     cfg = Config(descr)
     assert cfg.dummy is False
     assert cfg.getowner(gcdummy) == 'default'
+    raises(TypeError, "cfg.getowner('gcdummy')")
     cfg.dummy = True
     assert cfg.getowner(gcdummy) == owners.user
 
diff --git a/test/test_parsing_group.py b/test/test_parsing_group.py
index 7ecd860..c3b6ffc 100644
--- a/test/test_parsing_group.py
+++ b/test/test_parsing_group.py
@@ -94,6 +94,19 @@ def test_iter_on_groups():
     result = list(config.creole.iter_groups(group_type=groups.family))
     group_names = [res[0] for res in result]
     assert group_names == ['general', 'interface1']
+    for i in config.creole.iter_groups(group_type=groups.family):
+        #test StopIteration
+        break
+
+
+def test_iter_on_groups_props():
+    descr = make_description()
+    config = Config(descr)
+    config.read_write()
+    config.cfgimpl_get_settings()[descr.creole.interface1].append('disabled')
+    result = list(config.creole.iter_groups(group_type=groups.family))
+    group_names = [res[0] for res in result]
+    assert group_names == ['general']
 
 
 def test_iter_on_empty_group():
diff --git a/test/test_state.py b/test/test_state.py
index ef46ce2..03be06e 100644
--- a/test/test_state.py
+++ b/test/test_state.py
@@ -1,10 +1,13 @@
+import autopath
+
 from tiramisu.option import BoolOption, UnicodeOption, SymLinkOption, \
-    OptionDescription
-from tiramisu.config import Config
+    IntOption, OptionDescription
+from tiramisu.config import Config, GroupConfig, MetaConfig
 from tiramisu.setting import owners
 from tiramisu.storage import delete_session
 from tiramisu.error import ConfigError
 from pickle import dumps, loads
+from py.test import raises
 
 
 def return_value(value=None):
@@ -90,10 +93,48 @@ def _diff_opt(opt1, opt2):
             assert val1 == val2
 
 
+def _diff_conf(cfg1, cfg2):
+    attr1 = set(_get_slots(cfg1))
+    attr2 = set(_get_slots(cfg2))
+    diff1 = attr1 - attr2
+    diff2 = attr2 - attr1
+    if diff1 != set():
+        raise Exception('more attribute in cfg1 {0}'.format(list(diff1)))
+    if diff2 != set():
+        raise Exception('more attribute in cfg2 {0}'.format(list(diff2)))
+    for attr in attr1:
+        if attr in ('_impl_context', '__weakref__'):
+            continue
+        err1 = False
+        err2 = False
+        val1 = None
+        val2 = None
+        try:
+            val1 = getattr(cfg1, attr)
+        except:
+            err1 = True
+
+        try:
+            val2 = getattr(cfg2, attr)
+        except:
+            err2 = True
+        assert err1 == err2
+        if val1 is None:
+            assert val1 == val2
+        elif attr == '_impl_values':
+            assert cfg1.cfgimpl_get_values().get_modified_values() == cfg2.cfgimpl_get_values().get_modified_values()
+        elif attr == '_impl_settings':
+            assert cfg1.cfgimpl_get_settings().get_modified_properties() == cfg2.cfgimpl_get_settings().get_modified_properties()
+            assert cfg1.cfgimpl_get_settings().get_modified_permissives() == cfg2.cfgimpl_get_settings().get_modified_permissives()
+        elif attr == '_impl_descr':
+            _diff_opt(cfg1.cfgimpl_get_description(), cfg2.cfgimpl_get_description())
+        else:
+            assert val1 == val2
+
+
 def test_diff_opt():
     b = BoolOption('b', '')
     u = UnicodeOption('u', '', requires=[{'option': b, 'expected': True, 'action': 'disabled', 'inverse': True}])
-    #u.impl_add_consistency('not_equal', b)
     s = SymLinkOption('s', u)
     o = OptionDescription('o', '', [b, u, s])
     o1 = OptionDescription('o1', '', [o])
@@ -107,6 +148,11 @@ def test_diff_opt():
     _diff_opt(o1.o.s, q.o.s)
 
 
+def test_only_optiondescription():
+    b = BoolOption('b', '')
+    raises(SystemError, "a = dumps(b)")
+
+
 def test_diff_opt_cache():
     b = BoolOption('b', '')
     u = UnicodeOption('u', '', requires=[{'option': b, 'expected': True, 'action': 'disabled', 'inverse': True}])
@@ -169,10 +215,7 @@ def test_state_config():
         cfg._impl_test = True
     a = dumps(cfg)
     q = loads(a)
-    _diff_opt(maconfig, q.cfgimpl_get_description())
-    assert cfg.cfgimpl_get_values().get_modified_values() == q.cfgimpl_get_values().get_modified_values()
-    assert cfg.cfgimpl_get_settings().get_modified_properties() == q.cfgimpl_get_settings().get_modified_properties()
-    assert cfg.cfgimpl_get_settings().get_modified_permissives() == q.cfgimpl_get_settings().get_modified_permissives()
+    _diff_conf(cfg, q)
     try:
         delete_session('29090931')
     except ConfigError:
@@ -191,12 +234,9 @@ def test_state_properties():
     cfg.cfgimpl_get_settings()[val1].append('test')
     a = dumps(cfg)
     q = loads(a)
-    _diff_opt(maconfig, q.cfgimpl_get_description())
-    assert cfg.cfgimpl_get_values().get_modified_values() == q.cfgimpl_get_values().get_modified_values()
-    assert cfg.cfgimpl_get_settings().get_modified_properties() == q.cfgimpl_get_settings().get_modified_properties()
-    assert cfg.cfgimpl_get_settings().get_modified_permissives() == q.cfgimpl_get_settings().get_modified_permissives()
+    _diff_conf(cfg, q)
     try:
-        delete_session('29090931')
+        delete_session('29090932')
     except ConfigError:
         pass
 
@@ -212,15 +252,12 @@ def test_state_values():
     cfg.val1 = True
     a = dumps(cfg)
     q = loads(a)
-    _diff_opt(maconfig, q.cfgimpl_get_description())
-    assert cfg.cfgimpl_get_values().get_modified_values() == q.cfgimpl_get_values().get_modified_values()
-    assert cfg.cfgimpl_get_settings().get_modified_properties() == q.cfgimpl_get_settings().get_modified_properties()
-    assert cfg.cfgimpl_get_settings().get_modified_permissives() == q.cfgimpl_get_settings().get_modified_permissives()
+    _diff_conf(cfg, q)
     q.val1 = False
     #assert cfg.val1 is True
     assert q.val1 is False
     try:
-        delete_session('29090931')
+        delete_session('29090933')
     except ConfigError:
         pass
 
@@ -238,14 +275,94 @@ def test_state_values_owner():
     cfg.val1 = True
     a = dumps(cfg)
     q = loads(a)
-    _diff_opt(maconfig, q.cfgimpl_get_description())
-    assert cfg.cfgimpl_get_values().get_modified_values() == q.cfgimpl_get_values().get_modified_values()
-    assert cfg.cfgimpl_get_settings().get_modified_properties() == q.cfgimpl_get_settings().get_modified_properties()
-    assert cfg.cfgimpl_get_settings().get_modified_permissives() == q.cfgimpl_get_settings().get_modified_permissives()
+    _diff_conf(cfg, q)
     q.val1 = False
     nval1 = q.cfgimpl_get_description().val1
     assert q.getowner(nval1) == owners.newowner
     try:
-        delete_session('29090931')
+        delete_session('29090934')
     except ConfigError:
         pass
+
+
+def test_state_metaconfig():
+    i1 = IntOption('i1', '')
+    od1 = OptionDescription('od1', '', [i1])
+    od2 = OptionDescription('od2', '', [od1])
+    conf1 = Config(od2, session_id='29090935')
+    conf1._impl_test = True
+    conf2 = Config(od2, session_id='29090936')
+    conf2._impl_test = True
+    meta = MetaConfig([conf1, conf2], session_id='29090937')
+    meta._impl_test = True
+    raises(ConfigError, "dumps(meta)")
+    try:
+        delete_session('29090935')
+        delete_session('29090936')
+        delete_session('29090937')
+    except ConfigError:
+        pass
+
+
+def test_state_groupconfig():
+    i1 = IntOption('i1', '')
+    od1 = OptionDescription('od1', '', [i1])
+    od2 = OptionDescription('od2', '', [od1])
+    conf1 = Config(od2, session_id='29090935')
+    conf1._impl_test = True
+    conf2 = Config(od2, session_id='29090936')
+    conf2._impl_test = True
+    meta = GroupConfig([conf1, conf2], session_id='29090937')
+    meta._impl_test = True
+    a = dumps(meta)
+    q = loads(a)
+    _diff_conf(meta, q)
+    try:
+        delete_session('29090935')
+        delete_session('29090936')
+        delete_session('29090937')
+    except ConfigError:
+        pass
+
+
+def test_state_unkown_setting_owner():
+    """load an unknow _owner, should create it"""
+    assert not 'supernewuser' in owners.__dict__
+    loads("""ccopy_reg
+_reconstructor
+p0
+(ctiramisu.setting
+Settings
+p1
+c__builtin__
+object
+p2
+Ntp3
+Rp4
+(dp5
+S'_owner'
+p6
+S'supernewuser'
+p7
+sS'_p_'
+p8
+g0
+(ctiramisu.storage.dictionary.setting
+Settings
+p9
+g2
+Ntp10
+Rp11
+(dp12
+S'_cache'
+p13
+(dp14
+sS'_permissives'
+p15
+(dp16
+sS'_properties'
+p17
+(dp18
+sbsb.
+.""")
+    assert 'supernewuser' in owners.__dict__
diff --git a/tiramisu/autolib.py b/tiramisu/autolib.py
index ffdbb0a..cb3552a 100644
--- a/tiramisu/autolib.py
+++ b/tiramisu/autolib.py
@@ -152,7 +152,10 @@ def carry_out_calculation(option, config, callback, callback_params,
                     opt)
                 # get value
                 try:
-                    value = config._getattr(path, force_permissive=True)
+                    value = config._getattr(path, force_permissive=True, validate=False)
+                    # convert to list, not modifie this multi
+                    if value.__class__.__name__ == 'Multi':
+                        value = list(value)
                 except PropertiesOptionError as err:
                     if force_permissive:
                         continue
diff --git a/tiramisu/config.py b/tiramisu/config.py
index 4bc0e15..c9fb992 100644
--- a/tiramisu/config.py
+++ b/tiramisu/config.py
@@ -48,7 +48,7 @@ class SubConfig(object):
         :type subpath: `str` with the path name
         """
         # main option description
-        if not isinstance(descr, OptionDescription):
+        if descr is not None and not isinstance(descr, OptionDescription):
             raise TypeError(_('descr must be an optiondescription, not {0}'
                               ).format(type(descr)))
         self._impl_descr = descr
@@ -149,8 +149,6 @@ class SubConfig(object):
             except UnicodeEncodeError:
                 lines.append("{0} = {1}".format(name,
                                                 value.encode(default_encoding)))
-            except PropertiesOptionError:
-                pass
         return '\n'.join(lines)
 
     __repr__ = __str__
@@ -169,7 +167,7 @@ class SubConfig(object):
     def cfgimpl_get_description(self):
         if self._impl_descr is None:
             raise ConfigError(_('no option description found for this config'
-                                ' (may be metaconfig without meta)'))
+                                ' (may be GroupConfig)'))
         else:
             return self._impl_descr
 
@@ -298,12 +296,9 @@ class SubConfig(object):
         :return: find list or an exception if nothing has been found
         """
         def _filter_by_name():
-            try:
-                if byname is None or path == byname or \
-                        path.endswith('.' + byname):
-                    return True
-            except IndexError:
-                pass
+            if byname is None or path == byname or \
+                    path.endswith('.' + byname):
+                return True
             return False
 
         def _filter_by_value():
@@ -454,22 +449,16 @@ class SubConfig(object):
 
     def _make_sub_dict(self, opt, path, pathsvalues, _currpath, flatten):
         if isinstance(opt, OptionDescription):
-            try:
-                pathsvalues += getattr(self, path).make_dict(flatten,
-                                                             _currpath +
-                                                             path.split('.'))
-            except PropertiesOptionError:
-                pass  # this just a hidden or disabled option
+            pathsvalues += getattr(self, path).make_dict(flatten,
+                                                         _currpath +
+                                                         path.split('.'))
         else:
-            try:
-                value = self._getattr(opt._name)
-                if flatten:
-                    name = opt._name
-                else:
-                    name = '.'.join(_currpath + [opt._name])
-                pathsvalues.append((name, value))
-            except PropertiesOptionError:
-                pass  # this just a hidden or disabled option
+            value = self._getattr(opt._name)
+            if flatten:
+                name = opt._name
+            else:
+                name = '.'.join(_currpath + [opt._name])
+            pathsvalues.append((name, value))
 
     def cfgimpl_get_path(self):
         descr = self.cfgimpl_get_description()
@@ -477,9 +466,9 @@ class SubConfig(object):
         return context_descr.impl_get_path_by_opt(descr)
 
 
-class CommonConfig(SubConfig):
-    "abstract base class for the Config and the MetaConfig"
-    __slots__ = ('_impl_values', '_impl_settings', '_impl_meta')
+class _CommonConfig(SubConfig):
+    "abstract base class for the Config, GroupConfig and the MetaConfig"
+    __slots__ = ('_impl_values', '_impl_settings', '_impl_meta', '_impl_test')
 
     def _impl_build_all_paths(self):
         self.cfgimpl_get_description().impl_build_cache()
@@ -518,7 +507,8 @@ class CommonConfig(SubConfig):
         return None
 
     def cfgimpl_get_meta(self):
-        return self._impl_meta
+        if self._impl_meta is not None:
+            return self._impl_meta()
 
     # information
     def impl_set_information(self, key, value):
@@ -536,11 +526,48 @@ class CommonConfig(SubConfig):
         """
         return self._impl_values.get_information(key, default)
 
+    # ----- state
+    def __getstate__(self):
+        if self._impl_meta is not None:
+            raise ConfigError(_('cannot serialize Config with MetaConfig'))
+        slots = set()
+        for subclass in self.__class__.__mro__:
+            if subclass is not object:
+                slots.update(subclass.__slots__)
+        slots -= frozenset(['_impl_context', '_impl_meta', '__weakref__'])
+        state = {}
+        for slot in slots:
+            try:
+                state[slot] = getattr(self, slot)
+            except AttributeError:
+                pass
+        storage = self._impl_values._p_._storage
+        if not storage.serializable:
+            raise ConfigError(_('this storage is not serialisable, could be a '
+                              'none persistent storage'))
+        state['_storage'] = {'session_id': storage.session_id,
+                             'persistent': storage.persistent}
+        state['_impl_setting'] = _impl_getstate_setting()
+        return state
+
+    def __setstate__(self, state):
+        for key, value in state.items():
+            if key not in ['_storage', '_impl_setting']:
+                setattr(self, key, value)
+        set_storage(**state['_impl_setting'])
+        self._impl_context = weakref.ref(self)
+        self._impl_settings.context = weakref.ref(self)
+        self._impl_values.context = weakref.ref(self)
+        storage = get_storage(test=self._impl_test, **state['_storage'])
+        self._impl_values._impl_setstate(storage)
+        self._impl_settings._impl_setstate(storage)
+        self._impl_meta = None
+
 
 # ____________________________________________________________
-class Config(CommonConfig):
+class Config(_CommonConfig):
     "main configuration management entry"
-    __slots__ = ('__weakref__', '_impl_test')
+    __slots__ = ('__weakref__',)
 
     def __init__(self, descr, session_id=None, persistent=False):
         """ Configuration option management master class
@@ -564,41 +591,6 @@ class Config(CommonConfig):
         #undocumented option used only in test script
         self._impl_test = False
 
-    def __getstate__(self):
-        if self._impl_meta is not None:
-            raise ConfigError('cannot serialize Config with meta')
-        slots = set()
-        for subclass in self.__class__.__mro__:
-            if subclass is not object:
-                slots.update(subclass.__slots__)
-        slots -= frozenset(['_impl_context', '__weakref__'])
-        state = {}
-        for slot in slots:
-            try:
-                state[slot] = getattr(self, slot)
-            except AttributeError:
-                pass
-        storage = self._impl_values._p_._storage
-        if not storage.serializable:
-            raise ConfigError('this storage is not serialisable, could be a '
-                              'none persistent storage')
-        state['_storage'] = {'session_id': storage.session_id,
-                             'persistent': storage.persistent}
-        state['_impl_setting'] = _impl_getstate_setting()
-        return state
-
-    def __setstate__(self, state):
-        for key, value in state.items():
-            if key not in ['_storage', '_impl_setting']:
-                setattr(self, key, value)
-        set_storage(**state['_impl_setting'])
-        self._impl_context = weakref.ref(self)
-        self._impl_settings.context = weakref.ref(self)
-        self._impl_values.context = weakref.ref(self)
-        storage = get_storage(test=self._impl_test, **state['_storage'])
-        self._impl_values._impl_setstate(storage)
-        self._impl_settings._impl_setstate(storage)
-
     def cfgimpl_reset_cache(self,
                             only_expired=False,
                             only=('values', 'settings')):
@@ -608,99 +600,119 @@ class Config(CommonConfig):
             self.cfgimpl_get_settings().reset_cache(only_expired=only_expired)
 
 
-#class MetaConfig(CommonConfig):
-#    __slots__ = ('_impl_children',)
+class GroupConfig(_CommonConfig):
+    __slots__ = ('_impl_children', '__weakref__')
 
-#    def __init__(self, children, meta=True, session_id=None, persistent=False):
-#        if not isinstance(children, list):
-#            raise ValueError(_("metaconfig's children must be a list"))
-#        self._impl_descr = None
-#        self._impl_path = None
-#        if meta:
-#            for child in children:
-#                if not isinstance(child, CommonConfig):
-#                    raise TypeError(_("metaconfig's children "
-#                                      "must be config, not {0}"
-#                                      ).format(type(child)))
-#                if self._impl_descr is None:
-#                    self._impl_descr = child.cfgimpl_get_description()
-#                elif not self._impl_descr is child.cfgimpl_get_description():
-#                    raise ValueError(_('all config in metaconfig must '
-#                                       'have the same optiondescription'))
-#                if child.cfgimpl_get_meta() is not None:
-#                    raise ValueError(_("child has already a metaconfig's"))
-#                child._impl_meta = self
+    def __init__(self, children, session_id=None, persistent=False,
+                 _descr=None):
+        if not isinstance(children, list):
+            raise ValueError(_("metaconfig's children must be a list"))
+        self._impl_children = children
+        settings, values = get_storages(self, session_id, persistent)
+        self._impl_settings = Settings(self, settings)
+        self._impl_values = Values(self, values)
+        super(GroupConfig, self).__init__(_descr, weakref.ref(self))
+        self._impl_meta = None
+        #undocumented option used only in test script
+        self._impl_test = False
 
-#        self._impl_children = children
-#        settings, values = get_storages(self, session_id, persistent)
-#        self._impl_settings = Settings(self, settings)
-#        self._impl_values = Values(self, values)
-#        self._impl_meta = None
+    def cfgimpl_get_children(self):
+        return self._impl_children
 
-#    def cfgimpl_get_children(self):
-#        return self._impl_children
+    #def cfgimpl_get_context(self):
+    #    "a meta config is a config which has a setting, that is itself"
+    #    return self
+    #
+    def cfgimpl_reset_cache(self,
+                            only_expired=False,
+                            only=('values', 'settings')):
+        if 'values' in only:
+            self.cfgimpl_get_values().reset_cache(only_expired=only_expired)
+        if 'settings' in only:
+            self.cfgimpl_get_settings().reset_cache(only_expired=only_expired)
+        for child in self._impl_children:
+            child.cfgimpl_reset_cache(only_expired=only_expired, only=only)
 
-#    def cfgimpl_get_context(self):
-#        "a meta config is a config wich has a setting, that is itself"
-#        return self
+    def setattrs(self, path, value):
+        """Setattr not in current GroupConfig, but in each children
+        """
+        for child in self._impl_children:
+            try:
+                if not isinstance(child, GroupConfig):
+                    setattr(child, path, value)
+                else:
+                    child.setattrs(path, value)
+            except PropertiesOptionError:
+                pass
 
-#    def cfgimpl_reset_cache(self,
-#                            only_expired=False,
-#                            only=('values', 'settings')):
-#        if 'values' in only:
-#            self.cfgimpl_get_values().reset_cache(only_expired=only_expired)
-#        if 'settings' in only:
-#            self.cfgimpl_get_settings().reset_cache(only_expired=only_expired)
-#        for child in self._impl_children:
-#            child.cfgimpl_reset_cache(only_expired=only_expired, only=only)
+    def find_firsts(self, byname=None, bypath=None, byvalue=None,
+                    type_='path', display_error=True):
+        """Find first not in current GroupConfig, but in each children
+        """
+        ret = []
+        #if MetaConfig, all children have same OptionDescription as context
+        #so search only one time for all children
+        try:
+            if bypath is None and byname is not None and \
+                    isinstance(self, MetaConfig):
+                bypath = self._find(bytype=None, byvalue=None, byname=byname,
+                                    first=True, type_='path',
+                                    check_properties=False,
+                                    display_error=display_error)
+                byname = None
+        except AttributeError:
+            pass
+        for child in self._impl_children:
+            try:
+                if not isinstance(child, MetaConfig):
+                    if bypath is not None:
+                        #if byvalue is None, try if not raise
+                        value = getattr(child, bypath)
+                        if byvalue is not None:
+                            if isinstance(value, Multi):
+                                if byvalue in value:
+                                    ret.append(child)
+                            else:
+                                if value == byvalue:
+                                    ret.append(child)
+                        else:
+                            ret.append(child)
+                    else:
+                        ret.append(child.find_first(byname=byname,
+                                                    byvalue=byvalue,
+                                                    type_=type_,
+                                                    display_error=False))
+                else:
+                    ret.extend(child.find_firsts(byname=byname,
+                                                 bypath=bypath,
+                                                 byvalue=byvalue,
+                                                 type_=type_,
+                                                 display_error=False))
+            except AttributeError:
+                pass
+        return self._find_return_results(ret, display_error)
 
-#    def set_contexts(self, path, value):
-#        for child in self._impl_children:
-#            try:
-#                if not isinstance(child, MetaConfig):
-#                    setattr(child, path, value)
-#                else:
-#                    child.set_contexts(path, value)
-#            except PropertiesOptionError:
-#                pass
 
-#    def find_first_contexts(self, byname=None, bypath=None, byvalue=None,
-#                            type_='path', display_error=True):
-#        ret = []
-#        try:
-#            if bypath is None and byname is not None and \
-#                    self.cfgimpl_get_description() is not None:
-#                bypath = self._find(bytype=None, byvalue=None, byname=byname,
-#                                    first=True, type_='path',
-#                                    check_properties=False,
-#                                    display_error=display_error)
-#        except ConfigError:
-#            pass
-#        for child in self._impl_children:
-#            try:
-#                if not isinstance(child, MetaConfig):
-#                    if bypath is not None:
-#                        if byvalue is not None:
-#                            if getattr(child, bypath) == byvalue:
-#                                ret.append(child)
-#                        else:
-#                            #not raise
-#                            getattr(child, bypath)
-#                            ret.append(child)
-#                    else:
-#                        ret.append(child.find_first(byname=byname,
-#                                                    byvalue=byvalue,
-#                                                    type_=type_,
-#                                                    display_error=False))
-#                else:
-#                    ret.extend(child.find_first_contexts(byname=byname,
-#                                                         bypath=bypath,
-#                                                         byvalue=byvalue,
-#                                                         type_=type_,
-#                                                         display_error=False))
-#            except AttributeError:
-#                pass
-#        return self._find_return_results(ret, display_error)
+class MetaConfig(GroupConfig):
+    __slots__ = tuple()
+
+    def __init__(self, children, session_id=None, persistent=False):
+        descr = None
+        for child in children:
+            if not isinstance(child, _CommonConfig):
+                raise TypeError(_("metaconfig's children "
+                                  "should be config, not {0}"
+                                  ).format(type(child)))
+            if child.cfgimpl_get_meta() is not None:
+                raise ValueError(_("child has already a metaconfig's"))
+            if descr is None:
+                descr = child.cfgimpl_get_description()
+            elif not descr is child.cfgimpl_get_description():
+                raise ValueError(_('all config in metaconfig must '
+                                   'have the same optiondescription'))
+            child._impl_meta = weakref.ref(self)
+
+        super(MetaConfig, self).__init__(children, session_id, persistent, descr)
 
 
 def mandatory_warnings(config):
@@ -719,6 +731,4 @@ def mandatory_warnings(config):
         except PropertiesOptionError as err:
             if err.proptype == ['mandatory']:
                 yield path
-        except ConfigError:
-            pass
     config.cfgimpl_reset_cache(only=('values',))
diff --git a/tiramisu/option.py b/tiramisu/option.py
index 8b5eb68..b9960b6 100644
--- a/tiramisu/option.py
+++ b/tiramisu/option.py
@@ -354,9 +354,6 @@ class Option(BaseOption):
         """
         if context is not None:
             descr = context.cfgimpl_get_description()
-        #option is also in all_cons_opts
-        if option not in all_cons_opts:
-            raise ConfigError(_('option not in all_cons_opts'))
 
         all_cons_vals = []
         for opt in all_cons_opts:
@@ -587,31 +584,15 @@ class Option(BaseOption):
                 consistencies = self._state_consistencies
             else:
                 consistencies = self._consistencies
-            if isinstance(consistencies, list):
-                new_value = []
-                for consistency in consistencies:
-                    values = []
-                    for obj in consistency[1]:
-                        if load:
-                            values.append(descr.impl_get_opt_by_path(obj))
-                        else:
-                            values.append(descr.impl_get_path_by_opt(obj))
-                    new_value.append((consistency[0], tuple(values)))
-
-            else:
-                new_value = {}
-                for key, _consistencies in consistencies.items():
-                    new_value[key] = []
-                    for key_cons, _cons in _consistencies:
-                        _list_cons = []
-                        for _con in _cons:
-                            if load:
-                                _list_cons.append(
-                                    descr.impl_get_opt_by_path(_con))
-                            else:
-                                _list_cons.append(
-                                    descr.impl_get_path_by_opt(_con))
-                        new_value[key].append((key_cons, tuple(_list_cons)))
+            new_value = []
+            for consistency in consistencies:
+                values = []
+                for obj in consistency[1]:
+                    if load:
+                        values.append(descr.impl_get_opt_by_path(obj))
+                    else:
+                        values.append(descr.impl_get_path_by_opt(obj))
+                new_value.append((consistency[0], tuple(values)))
             if load:
                 del(self._state_consistencies)
                 self._consistencies = new_value
@@ -663,7 +644,7 @@ class ChoiceOption(Option):
         return self._open_values
 
     def _validate(self, value):
-        if not self._open_values and not value in self._values:
+        if not self.impl_is_openvalues() and not value in self.impl_get_values():
             raise ValueError(_('value {0} is not permitted, '
                                'only {1} is allowed'
                                '').format(value, self._values))
@@ -783,9 +764,13 @@ class IPOption(Option):
     def _validate(self, value):
         # sometimes an ip term starts with a zero
         # but this does not fit in some case, for example bind does not like it
-        for val in value.split('.'):
-            if val.startswith("0") and len(val) > 1:
-                raise ValueError(_('invalid IP'))
+        try:
+            for val in value.split('.'):
+                if val.startswith("0") and len(val) > 1:
+                    raise ValueError(_('invalid IP'))
+        except AttributeError:
+            #if integer for example
+            raise ValueError(_('invalid IP'))
         # 'standard' validation
         try:
             IP('{0}/32'.format(value))
@@ -857,18 +842,23 @@ class PortOption(Option):
         if self._allow_range and ":" in str(value):
             value = str(value).split(':')
             if len(value) != 2:
-                raise ValueError('invalid part, range must have two values '
-                                 'only')
+                raise ValueError(_('invalid part, range must have two values '
+                                 'only'))
             if not value[0] < value[1]:
-                raise ValueError('invalid port, first port in range must be'
-                                 ' smaller than the second one')
+                raise ValueError(_('invalid port, first port in range must be'
+                                 ' smaller than the second one'))
         else:
             value = [value]
 
         for val in value:
+            try:
+                int(val)
+            except ValueError:
+                raise ValueError(_('invalid port'))
             if not self._min_value <= int(val) <= self._max_value:
-                raise ValueError('invalid port, must be an between {0} and {1}'
-                                 ''.format(self._min_value, self._max_value))
+                raise ValueError(_('invalid port, must be an between {0} '
+                                    'and {1}').format(self._min_value,
+                                                    self._max_value))
 
 
 class NetworkOption(Option):
@@ -924,19 +914,14 @@ class NetmaskOption(Option):
                     IP('{0}/{1}'.format(val_ipnetwork, val_netmask),
                         make_net=not make_net)
                 except ValueError:
-                    if not make_net:
-                        msg = _("invalid network {0} ({1}) "
-                                "with netmask {2},"
-                                " this network is an IP")
+                    pass
                 else:
                     if make_net:
                         msg = _("invalid IP {0} ({1}) with netmask {2},"
                                 " this IP is a network")
 
         except ValueError:
-            if make_net:
-                msg = _('invalid IP {0} ({1}) with netmask {2}')
-            else:
+            if not make_net:
                 msg = _('invalid network {0} ({1}) with netmask {2}')
         if msg is not None:
             raise ValueError(msg.format(val_ipnetwork, opts[1]._name,
@@ -1032,8 +1017,8 @@ class DomainnameOption(Option):
         if self._type == 'domainname' and not self._allow_without_dot and \
                 '.' not in value:
             raise ValueError(_("invalid domainname, must have dot"))
-            if len(value) > 255:
-                raise ValueError(_("invalid domainname's length (max 255)"))
+        if len(value) > 255:
+            raise ValueError(_("invalid domainname's length (max 255)"))
         if len(value) < 2:
             raise ValueError(_("invalid domainname's length (min 2)"))
         if not self._domain_re.search(value):
@@ -1310,13 +1295,10 @@ class OptionDescription(BaseOption):
         if consistencies is not None:
             for func, all_cons_opts in consistencies:
                 #all_cons_opts[0] is the option where func is set
-                ret = all_cons_opts[0]._launch_consistency(func, option,
-                                                           value,
-                                                           context, index,
-                                                           all_cons_opts)
-                if ret is False:
-                    return False
-        return True
+                all_cons_opts[0]._launch_consistency(func, option,
+                                                     value,
+                                                     context, index,
+                                                     all_cons_opts)
 
     def _impl_getstate(self, descr=None):
         """enables us to export into a dict
diff --git a/tiramisu/value.py b/tiramisu/value.py
index a02196a..ed70f90 100644
--- a/tiramisu/value.py
+++ b/tiramisu/value.py
@@ -66,6 +66,8 @@ class Values(object):
         meta = self._getcontext().cfgimpl_get_meta()
         if meta is not None:
             value = meta.cfgimpl_get_values()[opt]
+            if isinstance(value, Multi):
+                value = list(value)
         else:
             value = opt.impl_getdefault()
         if opt.impl_is_multi():
@@ -73,7 +75,7 @@ class Values(object):
         else:
             return value
 
-    def _getvalue(self, opt, path, validate=True):
+    def _getvalue(self, opt, path):
         """actually retrieves the value
 
         :param opt: the `option.Option()` object
@@ -82,14 +84,9 @@ class Values(object):
         if not self._p_.hasvalue(path):
             # if there is no value
             value = self._getdefault(opt)
-            if opt.impl_is_multi():
-                value = Multi(value, self.context, opt, path, validate)
         else:
             # if there is a value
             value = self._p_.getvalue(path)
-            if opt.impl_is_multi() and not isinstance(value, Multi):
-                # load value so don't need to validate if is not a Multi
-                value = Multi(value, self.context, opt, path, validate=False)
         return value
 
     def get_modified_values(self):
@@ -198,7 +195,7 @@ class Values(object):
         # ConfigError if properties did not raise.
         config_error = None
         force_permissives = None
-        # if value is callback and is not set
+        # if value has callback and is not set
         # or frozen with force_default_on_freeze
         if opt.impl_has_callback() and (
                 self._is_default_owner(path) or
@@ -208,7 +205,7 @@ class Values(object):
             if (opt.impl_is_multi() and
                     opt.impl_get_multitype() == multitypes.slave):
                 masterp = self._get_opt_path(opt.impl_get_master_slaves())
-                mastervalue = getattr(context, masterp)
+                mastervalue = context._getattr(masterp, validate=validate)
                 lenmaster = len(mastervalue)
                 if lenmaster == 0:
                     value = []
@@ -240,7 +237,10 @@ class Values(object):
             if opt.impl_is_multi():
                 value = Multi(value, self.context, opt, path, validate)
         else:
-            value = self._getvalue(opt, path, validate)
+            value = self._getvalue(opt, path)
+            if opt.impl_is_multi():
+                # load value so don't need to validate if is not a Multi
+                value = Multi(value, self.context, opt, path, validate=validate)
         if config_error is None and validate:
             opt.impl_validate(value, context, 'validator' in setting)
         if config_error is None and self._is_default_owner(path) and \
@@ -266,10 +266,27 @@ class Values(object):
         context = self._getcontext()
         opt.impl_validate(value, context,
                           'validator' in context.cfgimpl_get_settings())
-        if opt.impl_is_multi() and not isinstance(value, Multi):
+        if opt.impl_is_multi():
             value = Multi(value, self.context, opt, path, setitem=True)
+            # Save old value
+            if opt.impl_get_multitype() == multitypes.master and \
+                    self._p_.hasvalue(path):
+                old_value = self._p_.getvalue(path)
+                old_owner = self._p_.getowner(path, None)
+            else:
+                old_value = undefined
+                old_owner = undefined
         self._setvalue(opt, path, value, force_permissive=force_permissive,
                        is_write=is_write)
+        if opt.impl_is_multi() and opt.impl_get_multitype() == multitypes.master:
+            try:
+                value._valid_master()
+            except Exception, err:
+                if old_value is not undefined:
+                    self._p_.setvalue(path, old_value, old_owner)
+                else:
+                    self._p_.resetvalue(path)
+                raise err
 
     def _setvalue(self, opt, path, value, force_permissive=False,
                   force_properties=None,
@@ -283,6 +300,8 @@ class Values(object):
                                         force_permissive=force_permissive,
                                         force_properties=force_properties)
         owner = context.cfgimpl_get_settings().getowner()
+        if isinstance(value, Multi):
+            value = list(value)
         self._p_.setvalue(path, value, owner)
 
     def getowner(self, opt):
@@ -403,6 +422,8 @@ class Multi(list):
         :param opt: the option object that have this Multi value
         :param setitem: only if set a value
         """
+        if isinstance(value, Multi):
+            raise ValueError(_('{0} is already a Multi ').format(opt._name))
         self.opt = opt
         self.path = path
         if not isinstance(context, weakref.ReferenceType):
@@ -412,8 +433,9 @@ class Multi(list):
             value = [value]
         if validate and self.opt.impl_get_multitype() == multitypes.slave:
             value = self._valid_slave(value, setitem)
-        elif validate and self.opt.impl_get_multitype() == multitypes.master:
-            self._valid_master(value)
+        elif not setitem and validate and \
+                self.opt.impl_get_multitype() == multitypes.master:
+            self._valid_master()
         super(Multi, self).__init__(value)
 
     def _getcontext(self):
@@ -433,12 +455,10 @@ class Multi(list):
         values = context.cfgimpl_get_values()
         masterp = context.cfgimpl_get_description().impl_get_path_by_opt(
             self.opt.impl_get_master_slaves())
-        mastervalue = getattr(context, masterp)
+        mastervalue = context._getattr(masterp, validate=False)
         masterlen = len(mastervalue)
         valuelen = len(value)
-        is_default_owner = not values._is_default_owner(self.path) or setitem
-        if valuelen > masterlen or (valuelen < masterlen and
-                                    is_default_owner):
+        if valuelen > masterlen or (valuelen < masterlen and setitem):
             raise SlaveError(_("invalid len for the slave: {0}"
                                " which has {1} as master").format(
                                    self.opt._name, masterp))
@@ -455,30 +475,12 @@ class Multi(list):
         #else: same len so do nothing
         return value
 
-    def _valid_master(self, value):
-        masterlen = len(value)
+    def _valid_master(self):
+        #masterlen = len(value)
         values = self._getcontext().cfgimpl_get_values()
         for slave in self.opt._master_slaves:
             path = values._get_opt_path(slave)
-            if not values._is_default_owner(path):
-                value_slave = values._getvalue(slave, path)
-                if len(value_slave) > masterlen:
-                    raise SlaveError(_("invalid len for the master: {0}"
-                                       " which has {1} as slave with"
-                                       " greater len").format(
-                                           self.opt._name, slave._name))
-                elif len(value_slave) < masterlen:
-                    for num in range(0, masterlen - len(value_slave)):
-                        if slave.impl_has_callback():
-                            # if callback add a value, but this value will not
-                            # change anymore automaticly (because this value
-                            # has owner)
-                            index = value_slave.__len__()
-                            value_slave.append(
-                                values._getcallback_value(slave, index=index),
-                                force=True)
-                        else:
-                            value_slave.append(undefined, force=True)
+            Multi(values._getvalue(slave, path), self.context, slave, path)
 
     def __setitem__(self, index, value):
         self._validate(value, index)
@@ -518,16 +520,15 @@ class Multi(list):
                         dvalue = values._getcallback_value(slave, index=index)
                     else:
                         dvalue = slave.impl_getdefault_multi()
-                    old_value = values.getitem(slave, path,
+                    old_value = values.getitem(slave, path, validate=False,
                                                validate_properties=False)
-                    if len(old_value) < self.__len__():
-                        values.getitem(slave, path,
-                                       validate_properties=False).append(
-                                           dvalue, force=True)
-                    else:
-                        values.getitem(slave, path,
-                                       validate_properties=False)[
-                                           index] = dvalue
+                    if len(old_value) + 1 != self.__len__():
+                        raise SlaveError(_("invalid len for the slave: {0}"
+                                           " which has {1} as master").format(
+                                               self.opt._name, self.__len__()))
+                    values.getitem(slave, path, validate=False,
+                                   validate_properties=False).append(
+                                       dvalue, force=True)
 
     def sort(self, cmp=None, key=None, reverse=False):
         if self.opt.impl_get_multitype() in [multitypes.slave,
@@ -592,12 +593,12 @@ class Multi(list):
             if self.opt.impl_get_multitype() == multitypes.slave:
                 raise SlaveError(_("cannot pop a value on a multi option {0}"
                                    " which is a slave").format(self.opt._name))
-            elif self.opt.impl_get_multitype() == multitypes.master:
+            if self.opt.impl_get_multitype() == multitypes.master:
                 for slave in self.opt.impl_get_master_slaves():
                     values = context.cfgimpl_get_values()
                     if not values.is_default_owner(slave):
                         #get multi without valid properties
-                        values.getitem(slave,
+                        values.getitem(slave, validate=False,
                                        validate_properties=False
                                        ).pop(index, force=True)
         #set value without valid properties
diff --git a/translations/fr/tiramisu.po b/translations/fr/tiramisu.po
index d9bbc3e..83a9289 100644
--- a/translations/fr/tiramisu.po
+++ b/translations/fr/tiramisu.po
@@ -79,7 +79,7 @@ msgstr "l'attribut {2} de l'objet '{0}' ({1}) est en lecture seule"
 
 #: tiramisu/option.py:141 tiramisu/value.py:376
 msgid "information's item not found: {0}"
-msgstr "aucune config spécifié alors que c'est nécessaire"
+msgstr "aucune config spécifiée alors que c'est nécessaire"
 
 #: tiramisu/option.py:203
 msgid "cannot serialize Option, only in OptionDescription"