Table instance_system_metadata's colume "value" is too short to contain the metadata, "Data too long for column 'value' at row 1"

It worked well in juno release, but in kilo, the error occurred. We'd like to insert some long metadata into instance_system_metadata, but it reported "Data too long for column 'value' at row 1".

2015-01-14 13:47:15.607 30360 ERROR oslo.db.sqlalchemy.exc_filters [-] DBAPIError exception wrapped from (DataError) (1406, "Data too long for column 'value' at row 1") 'INSERT INTO instance_system_metadata (created_at, updated_at, deleted_at, deleted, `key`, value, instance_uuid) VALUES (%s, %s, %s, %s, %s, %s, %s)' (datetime.datetime(2015, 1, 14, 5, 47, 15, 607004), None, None, 0, 'configuration_data', '{"present_disk": {"files": {"ovf-env.xml": "<ns0:Environment xmlns:ns0=\\"http://schemas.dmtf.org/ovf/environment/1\\" ns0:id=\\"vs0\\">\\n <ns0:PlatformSection>\\n <ns0:Locale>en</ns0:Locale>\\n </ns0:PlatformSection>\\n <ns0:PropertySection>\\n <Property ns0:key=\\"com.{secret}.system.networking.ipv4defaultgateway\\" ns0:value=\\"10.9.0.1\\" /><Property ns0:key=\\"com.{secret}.system.networking.hostname\\" ns0:value=\\"tet\\" /><Property ns0:key=\\"com.{secret}.adapter.networking.slotnumber.1\\" ns0:value=\\"179\\" /><Property ns0:key=\\"com.{secret}.system.networking.dnsIPaddresses\\" ns0:value=\\"\\" /><Property ns0:key=\\"com.{secret}.adapter.networking.usedhcpv4.1\\" ns0:value=\\"false\\" /><Property ns0:key=\\"com.{secret}.adapter.networking.ipv4addresses.1\\" ns0:value=\\"10.9.0.2\\" /><Property ns0:key=\\"com.{secret}.adapter.networking.ipv4netmasks.1\\" ns0:value=\\"255.255.252.0\\" /><Property ns0:key=\\"com.{secret}.system.networking.domainname\\" ns0:value=\\"novalocal\\" /><Property ns0:key=\\"com.{secret}.system.timezone\\" ns0:value=\\"\\" /></ns0:PropertySection>\\n</ns0:Environment>"}, "volume_label": "ovf-env", "name": "disk.ovf"}}', '10818cb4-d2ae-4b8b-8bd3-f44768092960')
2015-01-14 13:47:15.607 30360 TRACE oslo.db.sqlalchemy.exc_filters Traceback (most recent call last):
2015-01-14 13:47:15.607 30360 TRACE oslo.db.sqlalchemy.exc_filters File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 951, in _execute_context
2015-01-14 13:47:15.607 30360 TRACE oslo.db.sqlalchemy.exc_filters context)
2015-01-14 13:47:15.607 30360 TRACE oslo.db.sqlalchemy.exc_filters File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/default.py", line 436, in do_execute
2015-01-14 13:47:15.607 30360 TRACE oslo.db.sqlalchemy.exc_filters cursor.execute(statement, parameters)
2015-01-14 13:47:15.607 30360 TRACE oslo.db.sqlalchemy.exc_filters File "/usr/lib64/python2.7/site-packages/MySQLdb/cursors.py", line 205, in execute
2015-01-14 13:47:15.607 30360 TRACE oslo.db.sqlalchemy.exc_filters self.errorhandler(self, exc, value)
2015-01-14 13:47:15.607 30360 TRACE oslo.db.sqlalchemy.exc_filters File "/usr/lib64/python2.7/site-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
2015-01-14 13:47:15.607 30360 TRACE oslo.db.sqlalchemy.exc_filters raise errorclass, errorvalue
2015-01-14 13:47:15.607 30360 TRACE oslo.db.sqlalchemy.exc_filters DataError: (1406, "Data too long for column 'value' at row 1")
2015-01-14 13:47:15.607 30360 TRACE oslo.db.sqlalchemy.exc_filters
2015-01-14 13:47:15.610 30360 WARNING powervc.nova.driver.virt.powervc.driver [-] Created instance failed: (DataError) (1406, "Data too long for column 'value' at row 1") 'INSERT INTO instance_system_metadata (created_at, updated_at, deleted_at, deleted, `key`, value, instance_uuid) VALUES (%s, %s, %s, %s, %s, %s, %s)' (datetime.datetime(2015, 1, 14, 5, 47, 15, 607004), None, None, 0, 'configuration_data', '{"present_disk": {"files": {"ovf-env.xml": "<ns0:Environment xmlns:ns0=\\"http://schemas.dmtf.org/ovf/environment/1\\" ns0:id=\\"vs0\\">\\n <ns0:PlatformSection>\\n <ns0:Locale>en</ns0:Locale>\\n </ns0:PlatformSection>\\n <ns0:PropertySection>\\n <Property ns0:key=\\"com.{secret}.system.networking.ipv4defaultgateway\\" ns0:value=\\"10.9.0.1\\" /><Property ns0:key=\\"com.{secret}.system.networking.hostname\\" ns0:value=\\"tet\\" /><Property ns0:key=\\"com.{secret}.adapter.networking.slotnumber.1\\" ns0:value=\\"179\\" /><Property ns0:key=\\"com.{secret}.system.networking.dnsIPaddresses\\" ns0:value=\\"\\" /><Property ns0:key=\\"com.{secret}.adapter.networking.usedhcpv4.1\\" ns0:value=\\"false\\" /><Property ns0:key=\\"com.{secret}.adapter.networking.ipv4addresses.1\\" ns0:value=\\"10.9.0.2\\" /><Property ns0:key=\\"com.{secret}.adapter.networking.ipv4netmasks.1\\" ns0:value=\\"255.255.252.0\\" /><Property ns0:key=\\"com.{secret}.system.networking.domainname\\" ns0:value=\\"novalocal\\" /><Property ns0:key=\\"com.{secret}.system.timezone\\" ns0:value=\\"\\" /></ns0:PropertySection>\\n</ns0:Environment>"}, "volume_label": "ovf-env", "name": "disk.ovf"}}', '10818cb4-d2ae-4b8b-8bd3-f44768092960')

I believe this might be a defect that it should contain a long data into system metadata. Please look into it, thanks.