[LVM] Shrinking /home to increase /root failed [solved]

orschiro · 2014-05-22 10:23:08

Hi there,

Before doing anything wrong and risking data loss, I will better ask for your advice. I used the following commands to shrink my /home partition in order to increase /root:

# vgchange -a y

# e2fsck -f /dev/VolGroup00/Home

# resize2fs /dev/VolGroup00/Home 205G

# lvreduce -L 206G VolGroup00/Home

# lvextend -l +100%FREE VolGroup00/Arch

# e2fsck -f /dev/VolGroup00/Arch

# resize2fs /dev/VolGroup00/Arch

The initial size of the logical volume Home was 208GB according to lvdisplay. The volume Arch corresponds to my /root.

All commands completed successfully. However, on boot I get the following error:

Home: The filesystem size (according to the superblock) is 54525952 blocks
The physical size of the device is 54001664 blocks
Either the superblock or the partition table is likely to be corrupt!
Home: UNEXPECTED INCONSISTENCY: RUN fsck MANUALLY

I booted from a live disk and tried to run fsck manually. But it aborts with the same error.

What am I advised to do now?

Thanks!

Last edited by orschiro (2014-05-26 06:55:30)

Inxsible · 2014-05-22 14:31:05

Maybe because you didn't increase the your Home filesystem back to 206G from 205G

frostschutz · 2014-05-22 15:35:45

Filesystems don't like it when parts of their storage go missing. You have to get the missing parts back.

Find your LVM backups / archives ( /etc/lvm/archive ), see if there is a file that says "created *before* lvreduce -L 206G VolGroup00/Home". That file would tell you where the /home partition was allocated before you shrank it.

You can use vgcfgrestore to get back to that state of things. At that point your /home should be accessible again - or at least fsckable. (But of course the /root is broke then - can't have both).

1) Before doing anything else, make a backup of your /root files if you need one
2) Free some space so you can use snapshot before you fsck. If fsck messes up you really are in trouble.

The real interesting question is what went wrong with the shrink in the first place. Your commands look like they should have worked. Most likely the resize2fs failed somehow? since it still believes itself to be 208GiB large.

Last edited by frostschutz (2014-05-22 15:38:19)

orschiro · 2014-05-23 21:56:38

Thanks to both of you! I hope I can fix this. I now realise that I made a very stupid mistake. I booted from the live disk to run the commands above but had forgotten that my laptop was in hibernation before. Thus it resumed from hibernation. I rebooted the machine without actually paying attention that the laptop was in hibernation. On reboot I then received the error.

I guess this has caused the issue, correct?

Damn...I looked into /etc/lvm/archive as you advised. However, there are only three files and none of them is named as you had indicated it above.

Screenshot: http://i.imgur.com/8bTrEKV.jpg

Is there anything I can do without this lvm archive or is my system just totally screwed up now?

orschiro · 2014-05-26 06:55:17

Solved by reverting back the size changes of the logical volumes:

# lvresize -L -2G VolGroup00/Arch

# lvresize -L +2G VolGroup00/Home

Arch Linux

#1 2014-05-22 10:23:08

[LVM] Shrinking /home to increase /root failed [solved]

#2 2014-05-22 14:31:05

Re: [LVM] Shrinking /home to increase /root failed [solved]

#3 2014-05-22 15:35:45

Re: [LVM] Shrinking /home to increase /root failed [solved]

#4 2014-05-23 21:56:38

Re: [LVM] Shrinking /home to increase /root failed [solved]

#5 2014-05-26 06:55:17

Re: [LVM] Shrinking /home to increase /root failed [solved]

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