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:
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.