Re: SLES 11 SP4: can't mount btrfs

[Andrei Borzenkov <arvidjaar@gmail.com>]

26.10.2017 15:18, Lentes, Bernd пишет:
> 
>> -----Original Message-----
>> From: linux-btrfs-owner@vger.kernel.org 
>> [mailto:linux-btrfs-owner@vger.kernel.org] On Behalf Of Lentes, Bernd
>> Sent: Tuesday, October 24, 2017 6:44 PM
>> To: Btrfs ML <linux-btrfs@vger.kernel.org>
>> Subject: RE: SLES 11 SP4: can't mount btrfs
>>
>>
>>>
>>> A short-term alternative, if you've got a full backup of what SLES
>>> mounts as /, is to run a regular install, boot the system, and then
>>> extract the backup on top of /.  It's not perfect, but it should work
>>> well enough.
>>
>> That's what I'm currently trying. I will keep you informed.
>>
> 
> I was able to restore the root fs. I formatted the / partition with Btrfs 
> again and could restore the files from a backup.
> Everything seems to be there, I can mount the Btrfs manually.
> But booting does not work. My Btrfs resides on a logical volume. I changed 
> /boot/grub/menu.lst and /etc/fstab to point to the lv. Before it was 
> pointing to a UUID.
> But booting my SLES complains that it does not find the root fs. screenshot: 
> https://hmgubox.helmholtz-muenchen.de/f/2d6b374e8a8b40569d4f/?dl=1
> 
> I can manually mount from the booted SLES. So everything (Btrfs, lvm) seems 
> to be available. I added in menu.lst and fstab the path to the device node 
> (/dev/vg1/lv_root), which works on other systems the same way, the only 
> difference is there I have ext3.
> But SLES finds from where I don't know a UUID (see screenshot). This UUID is 
> commented out in fstab and replaced by /dev/vg1/lv_root. Using 
> /dev/vg1/lv_root I can manually mount my Btrfs without any problem.
> 
> Where does my SLES find that UUID ? It is not available unter 
> /dev/disk/by-uuid. Can I change that value ?
> 

root device information is stored in initrd, you need to rebuild it.
Just run mkinitrd after you boot system.