1. The engine didn't clean it up itself - after all , no mater
the reason, the operation has failed?
can't really answer without looking at the
logs, engine should cleanup
in case of a failure, there can be numerous reasons for cleanup to
fail (connectivity issues, bug, etc)
2. Why the query fail to see the disk , but I have managed to unlock
it?
could be a bug, but it would need some way to reproduce