Loss of access rights

When the GPFS daemon fails on the session node, all file systems on the node are forced unmounted. As a result, all DM access rights associated with any local session are lost.

After daemon recovery, when the old sessions are assumed and the events are resubmitted, there is no way of identifying events that were already being handled prior to the failure (outstanding events), nor is there a guarantee that objects have not been accessed or modified after the access rights were lost. The DM application must be able to recover consistently without depending on persistent access rights. For example, it could keep its own state of events in progress, or process events idempotently.

Similarly, when a specific file system is forced unmounted at the session node, all DM access rights associated with the file system are lost, although the events themselves prevail on the session queue. After the file system is remounted, DMAPI calls using existing tokens may fail due to insufficient access rights. Also, there is no guarantee that objects have not been accessed or modified after the access rights were lost.