Managing MC/ServiceGuard NFS A.11.11.03 and A.11.23.02 (June 2004)

Overview of MC/ServiceGuard NFS
Limitations of MC/ServiceGuard NFS
Chapter 1 9
Limitations of MC/ServiceGuard NFS
The following limitations apply to MC/ServiceGuard NFS:
• Applications lose their file locks when an NFS server package moves
to a new node. Therefore, any application that uses file locking must
reclaim its locks after an NFS server package fails over.
An application that loses its file lock due to an NFS package failover
does not receive any notification. If the server is also an NFS client,
it loses the NFS file locks obtained by client-side processes.
NOTE With MC/ServiceGuard NFS A.11.11.03 and A.11.23.02, you can
address this limitation by enabling the File Lock Migration feature
(see “Overview of the NFS File Lock Migration Feature” on page 10).
To ensure that the File Lock Migration feature functions properly,
install HP-UX 11i v1 NFS General Release and Performance Patch,
PHNE_26388 (or a superseding patch). For HP-UX 11i v2, the
feature functions properly without a patch.
• If a server is configured to use NFS over TCP and the client is the
same machine as the server, which results in a loopback NFS mount,
the client may hang for about 5 minutes if the package is moved to
another node. The solution is to use NFS over UDP between
NFS-HA-server cross mounts.
NOTE You cannot use MC/ServiceGuard NFS for an NFS diskless cluster
server.
B5140-90020.book Page 9 Thursday, June 3, 2004 5:04 PM