NAME
clurmtabd - Cluster NFS Remote Mount Table Daemon
DESCRIPTION
Instances of
clurmtabd
keep entries relevant to a given mount point in sync cluster-wide. It does
this by polling /var/lib/nfs/rmtab periodically.
HOW IT WORKS
A single instance of
clurmtabd
is spawned by the service manager (clusvcmgrd(8)) for each mount point in a
given user service. Each instance polls /var/lib/nfs/rmtab every few seconds,
looking for changes. When changes are detected, they are merged in with the
current in-memory view. The entries are filtered according to the mount point
being monitored and are subsequently written out synchronously to that
mount point.
When a user service is relocated (or after a fail-over), clurmtabd reads the
entries on a given mount point and synchronizes them with the new member's
/var/lib/nfs/rmtab. This is done prior to running the exportfs(8) command
so that clients of the given service do not receive "Stale NFS file handle"
errors.
NOTES
Clurmtabd is not a part of NFS and can not ensure that "Stale NFS file handle"
errors are never received. It is a best-effort attempt. To fully prevent
"Stale NFS file handle" errors, it is necessary to modify the Linux kernel
as well as nfs-utils.
FILES
/var/lib/nfs/rmtab
SEE ALSO
clurgmgrd(8), rpc.mountd(8), exportfs(8)