Exception executing SQL update .. java.sql.SQLException: Error writing file (Errcode: 28)

2014-08-11 12:33:24,370 ERROR [active-objects-ddl-0]  net.java.ao.sql Exception executing SQL update <ALTER TABLE AO_FB71B4_SSH_PUBLIC_KEY CHANGE COLUMN KEY_TEXT KEY_TEXT LONGTEXT NOT NULL>
java.sql.SQLException: Error writing file './stash/#sql-317d_84.frm' (Errcode: 28)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1078) ~[mysql-connector-java-5.1.24-bin.jar:na]
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4120) ~[mysql-connector-java-5.1.24-bin.jar:na]
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4052) ~[mysql-connector-java-5.1.24-bin.jar:na]
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2503) ~[mysql-connector-java-5.1.24-bin.jar:na]
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2664) ~[mysql-connector-java-5.1.24-bin.jar:na]
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2809) ~[mysql-connector-java-5.1.24-bin.jar:na]
	at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1811) ~[mysql-connector-java-5.1.24-bin.jar:na]
	at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1725) ~[mysql-connector-java-5.1.24-bin.jar:na]
	at com.jolbox.bonecp.StatementHandle.executeUpdate(StatementHandle.java:536) ~[bonecp-0.7.1.RELEASE.jar:0.7.1.RELEASE]
	at net.java.ao.DatabaseProvider.executeUpdate(DatabaseProvider.java:2309) [activeobjects-plugin-0.25.2.jar:na]
	at net.java.ao.DatabaseProvider.executeUpdateForAction(DatabaseProvider.java:2379) [activeobjects-plugin-0.25.2.jar:na]
	at net.java.ao.DatabaseProvider.executeUpdatesForActions(DatabaseProvider.java:2342) [activeobjects-plugin-0.25.2.jar:na]
	at net.java.ao.schema.SchemaGenerator.migrate(SchemaGenerator.java:99) [activeobjects-plugin-0.25.2.jar:na]
	at net.java.ao.EntityManager.migrate(EntityManager.java:128) [activeobjects-plugin-0.25.2.jar:na]
	at com.atlassian.activeobjects.internal.EntityManagedActiveObjects.migrate(EntityManagedActiveObjects.java:48) [activeobjects-plugin-0.25.2.jar:na]
	at com.atlassian.activeobjects.internal.AbstractActiveObjectsFactory$1.doInTransaction(AbstractActiveObjectsFactory.java:65) [activeobjects-plugin-0.25.2.jar:na]
	at com.atlassian.activeobjects.internal.AbstractActiveObjectsFactory$1.doInTransaction(AbstractActiveObjectsFactory.java:59) [activeobjects-plugin-0.25.2.jar:na]
	at com.atlassian.sal.core.transaction.HostContextTransactionTemplate$1.doInTransaction(HostContextTransactionTemplate.java:25) [sal-core-2.11.0.jar:na]
	at com.atlassian.stash.internal.sal.spi.HostContextAccessorImpl.doInTransaction(HostContextAccessorImpl.java:27) [stash-platform-3.0.4.jar:na]
	at com.sun.proxy.$Proxy197.doInTransaction(Unknown Source) [na:na]
	at com.sun.proxy.$Proxy279.doInTransaction(Unknown Source) [na:na]
	at com.sun.proxy.$Proxy484.doInTransaction(Unknown Source) [na:na]
	at com.atlassian.sal.core.transaction.HostContextTransactionTemplate.execute(HostContextTransactionTemplate.java:21) [sal-core-2.11.0.jar:na]
	at com.sun.proxy.$Proxy382.execute(Unknown Source) [na:na]
	at com.atlassian.activeobjects.internal.AbstractActiveObjectsFactory.create(AbstractActiveObjectsFactory.java:58) [activeobjects-plugin-0.25.2.jar:na]
	at com.atlassian.activeobjects.internal.DelegatingActiveObjectsFactory.create(DelegatingActiveObjectsFactory.java:40) [activeobjects-plugin-0.25.2.jar:na]
	at com.atlassian.activeobjects.osgi.ActiveObjectsServiceFactory.createActiveObjects(ActiveObjectsServiceFactory.java:160) [activeobjects-plugin-0.25.2.jar:na]
	at com.atlassian.activeobjects.osgi.ActiveObjectsServiceFactory.access$1100(ActiveObjectsServiceFactory.java:51) [activeobjects-plugin-0.25.2.jar:na]
	at com.atlassian.activeobjects.osgi.ActiveObjectsServiceFactory$6.call(ActiveObjectsServiceFactory.java:224) [activeobjects-plugin-0.25.2.jar:na]
	at com.atlassian.activeobjects.osgi.ActiveObjectsServiceFactory$6.call(ActiveObjectsServiceFactory.java:216) [activeobjects-plugin-0.25.2.jar:na]
	at java.util.concurrent.FutureTask.run(FutureTask.java:262) [na:1.7.0_65]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [na:1.7.0_65]
	at java.lang.Thread.run(Thread.java:745) [na:1.7.0_65]
	... 54 frames trimmed