3.7.0 HP StorageWorks HP Scalable NAS File Serving Software command reference guide HP Scalable NAS for Linux (AG513-96003, October 2009)

By default, the NLM locking protocol is disabled in the FS Option for Linux
software-only product. If necessary, NLM can be enabled; however, you should be
aware of the following caveat:
• File locks granted by the NFS server are cluster-coherent. When a failover occurs,
the locks are released by the original server and the client automatically reclaims
them on the new server (the backup node). However, during the period after the
lock is released, another client or application may compete for and win the lock.
Some NFS clients will return an error to the client applications if the lock cannot
be reclaimed. Other clients (for example, the Linux 2.6 NFS client) will not return
any error. If no error is returned by the client, the application may proceed under
the false assumption that the lock has been granted. Data corruption may be the
result. To prevent this situation, locking should be enabled only if your clients are
partitioned so that all clients needing a particular lock are using the same Virtual
NFS Service IP address. If a failover occurs, all of the clients will lose their locks.
They can then reclaim those same locks on the new node without conflicts from
outside clients.
The options are:
-q
Show the current status of NLM locking in the cluster (either enabled or disabled).
-e
Enable NLM locking in the cluster. No reboot is necessary; the change is effective
almost immediately and may affect clients.
-d
Disable NLM locking in the cluster. No reboot is necessary; the change is effective
almost immediately and may affect clients.
mxsancheck – check server’s SAN access
Synopsis
/opt/hpcfs/bin/mxsancheck
Description
The mxsancheck command determines whether a server has SAN access and is
ready to mount filesystems. The command is intended to be used in scripts and returns
0 on success and 1 on failure.
Cluster commands52