[opensuse-factory] Recovering after a BTRFS failure with Snapper

Robert Munteanu

30 Jul 2015 30 Jul '15

13:13

Hi, I've managed to hose my BTRFS root partition pretty badly, but in the end I was able to repair it and to boot from a snapper snapshot. Now the problem is that I can't rollback using snapper. The grub menu entry instructs me to use 'snapper rollback 301', where 301 is the id of the snapper snapshot. When I try to do that after booting it complains that Creating read-only snaphshot of current system. IO Error. Running snapper list shows that I have a no snapshots created ( only 'current' one is available ) and indeed /.snapshots is empty. How can I rollback to this state? Thanks, Robert -- http://robert.muntea.nu/ -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org

Show replies by date

Robert Munteanu

30 Jul 30 Jul

14:26

New subject: [opensuse-factory] Re: Recovering after a BTRFS failure with Snapper

On Thu, Jul 30, 2015 at 4:13 PM, Robert Munteanu wrote:

...

Hi,

I've managed to hose my BTRFS root partition pretty badly, but in the end I was able to repair it and to boot from a snapper snapshot.

Now the problem is that I can't rollback using snapper. The grub menu entry instructs me to use 'snapper rollback 301', where 301 is the id of the snapper snapshot.

When I try to do that after booting it complains that

Creating read-only snaphshot of current system. IO Error.

Running snapper list shows that I have a no snapshots created ( only 'current' one is available ) and indeed /.snapshots is empty.

So apparently I needed to mount -t btrfs -o subvol=.snapshots /dev/sda1 /.snapshots Why isn't this the default? Robert -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org

Andrei Borzenkov

15:21

New subject: [opensuse-factory] Re: Recovering after a BTRFS failure with Snapper

В Thu, 30 Jul 2015 17:26:24 +0300 Robert Munteanu пишет:

...

On Thu, Jul 30, 2015 at 4:13 PM, Robert Munteanu wrote:

...
Hi,

I've managed to hose my BTRFS root partition pretty badly, but in the end I was able to repair it and to boot from a snapper snapshot.

Now the problem is that I can't rollback using snapper. The grub menu entry instructs me to use 'snapper rollback 301', where 301 is the id of the snapper snapshot.

When I try to do that after booting it complains that

Creating read-only snaphshot of current system. IO Error.

Running snapper list shows that I have a no snapshots created ( only 'current' one is available ) and indeed /.snapshots is empty.

So apparently I needed to

mount -t btrfs -o subvol=.snapshots /dev/sda1 /.snapshots

Why isn't this the default?

I'd say it is a bug in snapper. subvolume .snapshots is still there and its content is obviously there. snapper should list content of subvolume, not content of /.snapshots directory. -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org

Michael Chang

31 Jul 31 Jul

02:25

New subject: [opensuse-factory] Re: Recovering after a BTRFS failure with Snapper

On Thu, Jul 30, 2015 at 05:26:24PM +0300, Robert Munteanu wrote:

...

On Thu, Jul 30, 2015 at 4:13 PM, Robert Munteanu wrote:

...
Hi,

I've managed to hose my BTRFS root partition pretty badly, but in the end I was able to repair it and to boot from a snapper snapshot.

Now the problem is that I can't rollback using snapper. The grub menu entry instructs me to use 'snapper rollback 301', where 301 is the id of the snapper snapshot.

That description is outdated and not correct, now you should run 'snapper rollback' without id to rollback changes to currently booted snapshot. I'll fix grub package for that description. Thanks, Michael -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org

Andrei Borzenkov

3 Aug 3 Aug

19:35

New subject: [opensuse-factory] Re: Recovering after a BTRFS failure with Snapper

В Fri, 31 Jul 2015 10:25:42 +0800 Michael Chang пишет:

...

On Thu, Jul 30, 2015 at 05:26:24PM +0300, Robert Munteanu wrote:

...
On Thu, Jul 30, 2015 at 4:13 PM, Robert Munteanu wrote:

...
Hi,

I've managed to hose my BTRFS root partition pretty badly, but in the end I was able to repair it and to boot from a snapper snapshot.

Now the problem is that I can't rollback using snapper. The grub menu entry instructs me to use 'snapper rollback 301', where 301 is the id of the snapper snapshot.

That description is outdated and not correct, now you should run 'snapper rollback' without id to rollback changes to currently booted snapshot. I'll fix grub package for that description.

I just tried "snapper rollback" on a current TW and I just get back "Creating read-only snapshot of default subvolume.IO error.". No snapshot was created, no default subvolume was changed, no rollback performed. Once I mounted /.snapshots it worked. So, without /.snapshots mount it does not work either way and with /.snapshots mount it works either way :) Granted, "snapper rollback" is easier, no need to know snapshot number. TW was installed couple of months ago, I do not know whether installer adds /.snapshots mount point now. -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org

Michael Chang

4 Aug 4 Aug

03:03

New subject: [opensuse-factory] Re: Recovering after a BTRFS failure with Snapper

On Mon, Aug 03, 2015 at 10:35:20PM +0300, Andrei Borzenkov wrote:

...

В Fri, 31 Jul 2015 10:25:42 +0800 Michael Chang пишет:

...
On Thu, Jul 30, 2015 at 05:26:24PM +0300, Robert Munteanu wrote:

...
On Thu, Jul 30, 2015 at 4:13 PM, Robert Munteanu wrote:

...
Hi,

I've managed to hose my BTRFS root partition pretty badly, but in the end I was able to repair it and to boot from a snapper snapshot.

Now the problem is that I can't rollback using snapper. The grub menu entry instructs me to use 'snapper rollback 301', where 301 is the id of the snapper snapshot.

That description is outdated and not correct, now you should run 'snapper rollback' without id to rollback changes to currently booted snapshot. I'll fix grub package for that description.

I just tried "snapper rollback" on a current TW and I just get back "Creating read-only snapshot of default subvolume.IO error.". No snapshot was created, no default subvolume was changed, no rollback performed.

I'm not sure whether snapper could do better by detecting the /.snapshot is in mounted and display more useful messages, the errors is discouraging to users.

...

Once I mounted /.snapshots it worked. So, without /.snapshots mount it does not work either way and with /.snapshots mount it works either way :) Granted, "snapper rollback" is easier, no need to know snapshot number.

Yes, it's more error proof so that it's why we suggested.

...

TW was installed couple of months ago, I do not know whether installer adds /.snapshots mount point now.

I think it should be, at least from my installation it works fine. Thanks. Michael -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org

3199

Age (days ago)

3204

Last active (days ago)

List overview

Download

5 comments

3 participants

participants (3)

Andrei Borzenkov
Michael Chang
Robert Munteanu