FC6, NFS V3 ----------- I'm trying to get to the state where 1. I can have a bunch of NFS clients which have mounted filesystems exported by a fileserver, 2. The fileserver is stopped, the (SCSI) disks containing the filesystems are moved to different positions on the SCSI bus, and the fileserver is rebooted. 3. The clients can still continue to access the correct filesystems, without having to umount/re-mount anything, even though their position on the server's SCSI bus has changed. The clients are members of a compute farm. They mount the NFS filesystems with the 'hard' option so that their NFS requests stall if the server is off for any reason, and so far this works well. However, if the server disks are moved, there are problems. I started off mounting the server filesystems by label, with lines in /etc/fstab like: LABEL=/filesys1 /filesystem1 ext3 defaults 0 2 This gave me pseudo-persistence in that wherever the disks were on the SCSI bus, they were always mounted on the correct mountpoint. With this setup, the underlying device (/dev/sda /dev/sdb etc) as shown by 'mount -t ext3' changed when the disk position changed. I then discovered that if I swapped two disks over on the server while those filesystems were still NFS-mounted by a client, the client didnt notice the swap, but continued to access the disks in the unswapped position, and hence access the wrong filesystem. There were no NFS complaints, just complaints from users. I'm now using a bunch of udev rules to give me device-name persistence instead of relying on the partition label, and I have lines in fstab like: /dev/dsk0_1 /filesystem1 ext3 defaults 0 2 Now, wherever I shift a disk to on the server SCSI bus, the underlying device-name stays constant, but the client objects with a 'stale NFS filehandle' error when the disk-position is changed, and I have to umount and remount at the client. Its a slight improvement in that user-processes on the client cant inadvertently use the wrong filesystem, but I would much prefer it to be transparent. Is this possible with NFS Cheers, Terry
