Why not just umount /dev/u, exposing /u directory which is now under root.
Restore the /u filesystem, change /etc/default/filesys to not mount /dev/u
to /u.

brian@aljex.com <brian@aljex.com>
>Yes, but it's not possible without doing a full tape backup & restore.

>Any of the supertars can fdisk and reformat a hard drive during restore
>so using one of those you can do a full master backup, with bit-level
>verify enabled, then do another, and if both suceeded without error
>then you can boot to the restore floppy, use the recovery software
>advanced options to override the defaults and create one big fs (don't
>forget to retain swap and recovery spaces though) and then restore onto
>that, and /u will just be a directory after that.

>I suggest doing the restore onto another disk rather than blowing away
>the original disk however.
>There is certainly a lot of ways to botch this and if you are asking
>the question then you obviously do do this routinely, and so, better
>restore onto a different disk so that you can always plug the original
>disk back in and resume running on that no matter what happens.

>supertars = backupedge / lonetar / ctar
>install any of their demos if you don't have one of them already, then
>buy it and instruct the customer to change tapes every day and take one
>home every night.