fstab & LVM logical volumes

[Derek Broughton]

ubuntu prole wrote:

> I installed 7.10 on LVM following these instructions (
> http://www.debuntu.org/how-to-install-ubuntu-over-lvm-filesystem ) and
> everything is working perfectly.
> 
> I want to allocate some of the free space contained within the volume and
> so
> I allocated another logical volume.  However when I go to add it to
> /etc/fstab the UUID provided by lvdisplay doesn't work.
> 
> Does anyone know how to get the proper UUID for the logical volume?

"sudo vol_id" for the correct /dev/mapper device.

...but yeah, the UUID reported by lvdisplay isn't the same as the one
reported by vol_id:

$ sudo lvdisplay /dev/linux/usr | grep UUID
  LV UUID                qYrxq3-Ozpt-4UEf-keka-17WD-q41M-fl8Uxy
$ sudo vol_id /dev/mapper/linux-usr | grep UUID
ID_FS_UUID=54e3ee84-bd34-48a7-b27e-b5db621fd661

> 
> I've also tried using the /dev/mapper entry in fstab but I get a message
> saying that the mount point doesn't exist.

The _mount point_ doesn't exist.  /dev/mapper/xxx is a block device, not the
mount point.  You still have to "mkdir" a mount point where you're going to
mount this.  E.G., my /usr partition is on LVM, and the block device
is /dev/mapper/linux-usr.  The mount point is /usr:

  /dev/mapper/linux-usr /usr jfs  defaults 0 2
-- 
derek