PSA: NFS Locking in RHEL6 Needs Reverse Lookup of NFS Server

The RHEL6 version of rpc.statd needs to be able to reverse lookup a hostname for the IP address of your NFS server if you want to lock files mounted from that server. If you don't have a reverse lookup for the IP of your NFS server, just throw its IP and some kind of name for it in /etc/hosts.

Otherwise you get errors in syslog to the effect of:

Feb 23 13:14:57 wardentest3 rpc.statd[1259]: No canonical hostname found for 10.238.3.20
Feb 23 13:14:57 wardentest3 rpc.statd[1259]: STAT_FAIL to wardentest3.geneseo.edu for SM_MON of 10.238.3.20
Feb 23 13:14:57 wardentest3 kernel: lockd: cannot monitor 10.238.3.20

Netapp + Rquotad + NFS + RHEL5

Those mounting volumes via NFS on a Netapp filer wanting to use rquotad on a volume with qtrees may notice that, under some conditions, things do not work.

If you are using qtrees, you can still get rquota to work by mounting each qtree individually, each with the "nosharecache" option. This forces each mounted qtree to have different st_dev values so that remote quota calls are enabled for all mounted qtrees, instead of just the first one. Without "nosharecache", all mounts from a volume on a Netapp filer will have the same st_dev value and any rquota calls will only query the first mounted qtree.

See http://linux.die.net/man/5/nfs for info on the "nosharecache" . . . there are some caveats to using it.