This was discovered by the SOA-P testing, and reported under SOA-2594. Basically, several FileSystemConnector unit tests attempt to test the maximum absolute path, and fail on IBM JDK 1.6.

The maximum absolute path length (255) for source "Test Repository" was exceeded by the node at: /qa/services/hudson/hudson_workspace/workspace/soa-modeshape-os-jdk16/jdk/ibm16/label/RHEL5_x86_res/modeshape/extensions/modeshape-connector-filesystem/target/repositories/test/test/test/test/test/test/test/test/test/test/test/test/test/test/test/test/test (0)
Stacktrace

org.modeshape.graph.connector.RepositorySourceException: The maximum absolute path length (255) for source "Test Repository" was exceeded by the node at: /qa/services/hudson/hudson_workspace/workspace/soa-modeshape-os-jdk16/jdk/ibm16/label/RHEL5_x86_res/modeshape/extensions/modeshape-connector-filesystem/target/repositories/test/test/test/test/test/test/test/test/test/test/test/test/test/test/test/test/test (0)
at org.modeshape.connector.filesystem.FileSystemWorkspace.ensureValidPathLength(FileSystemWorkspace.java:725)
at org.modeshape.connector.filesystem.FileSystemWorkspace.ensureValidPathLength(FileSystemWorkspace.java:702)
at org.modeshape.connector.filesystem.FileSystemWorkspace.validate(FileSystemWorkspace.java:698)
at org.modeshape.connector.filesystem.FileSystemRepository$FileSystemTransaction.validateNode(FileSystemRepository.java:190)
at org.modeshape.connector.filesystem.FileSystemRepository$FileSystemTransaction.validateNode(FileSystemRepository.java:151)
at org.modeshape.graph.connector.base.PathTransaction$WorkspaceChanges.created(PathTransaction.java:871)
at org.modeshape.graph.connector.base.PathTransaction.addChild(PathTransaction.java:335)
at org.modeshape.graph.connector.base.PathTransaction.addChild(PathTransaction.java:58)
at org.modeshape.graph.connector.base.Processor.process(Processor.java:317)
at org.modeshape.graph.request.processor.RequestProcessor.process(RequestProcessor.java:240)
at org.modeshape.graph.connector.base.Connection.execute(Connection.java:115)
at org.modeshape.graph.Graph.execute(Graph.java:283)
at org.modeshape.graph.Graph$5.process(Graph.java:226)
at org.modeshape.graph.request.RequestBuilder.createNode(RequestBuilder.java:289)
at org.modeshape.graph.Graph$13.submit(Graph.java:1342)
at org.modeshape.graph.Graph$13.submit(Graph.java:1335)
at org.modeshape.graph.Graph$CreateAction.and(Graph.java:7995)
at org.modeshape.connector.filesystem.FileSystemConnectorWritableTest.shouldBeAbleToCreateDeepPath(FileSystemConnectorWritableTest.java:523)