7.15 (SPARC Only) NFSv4 Delegation Interferes with Cluster Heartbeat, Using NFSv3 Results in RPC Error PROGRAM/VERSION MISMATCH

Server pool clustering on SPARC based server pools can cause servers to automatically fence due to NFSv4 write delegation revocation timeouts which exceed the timeout value for the cluster.

It is not possible to use NFSv3 as this results in an RPC error reporting a "PROGRAM/VERSION MISMATCH" and can cause the cluster database to hang due to the NFSv3 locking mechanism. This is expected behavior.

Workaround: There is no workaround for this issue. Only NFSv4 is supported for SPARC clustering, and you must disable delegation for this to work.

Bugs 18997487, 20443098, 21317571