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nfs_exporting_the_wrong_disk

If you going to export a disk from NFS, you need to be aware that it can be a bit picky about the volumes blkid. I found this issue by restoring multiple copies of a VM (from different days backups), and want wanting to export out each copy. On the NFS server, each volume was proper, but NFS was exporting out only one version.

So I had:

export
   +---backup1
   +---backup2

Which looked fine on the server, but on the client it was showing the same volume.

I traced it back to the UUID of the volume (and not the LVM UUID).

If you run this command:

blkid /dev/<vg_name>/logical volume>

You will get back the blkid of the volume. This is what NFS uses to export the volume. You can see this by running this command:

cat /proc/fs/nfsd/exports

You will see that as part of the mounted disks, the UUID listing. And in my case I saw the same UUID.

So I umounted on the client, stopped the NFS export and then ran this command command to change the UUID of the volume:

tune2fs /dev/<vg_name>/logical volume> -U  `uuidgen`

Check the blkid again and ensure that everything is good and then re-export.

nfs_exporting_the_wrong_disk.txt · Last modified: 2016/07/29 13:26 by The SuperUser