scrub resume after suspend not working

scrub resume after suspend not working

[Robert Krig]

Hi guys. 

I have a backup server which is running a BTRFS raid10. This server is
in the bedroom. So I have it set to suspend at night because of the
noise, and then a systemd timer which resumes it at 07:00 a.m the next
morning.

As part of the suspend/resume script i issue a btrfs cancel before
suspending and a btrfs scrub resume when the server wakes up again.

I've noticed however that after a suspend the btrfs scrub resume
doesn't seem to work properly. It just never finishes, even if the
original estimate (before the resume) was roughly about 20hours, which
it should have finished in one or two days.

After waking up from a suspend, the btrfs scrub resume does indeed
"resume" but it seems to have forgotten it's progress. It "looks" as
though it just started over. 

Is this expected behavior or is it a bug?


I'm running Debian Buster with backported Kernel 5.4.0 and btrfs
version 5.4.1

Re: scrub resume after suspend not working

[Holger Hoffstätte]

On 2/24/20 10:39 AM, Robert Krig wrote:
[snip]
> After waking up from a suspend, the btrfs scrub resume does indeed
> "resume" but it seems to have forgotten it's progress. It "looks" as
> though it just started over.
> 
> Is this expected behavior or is it a bug?

It *was* a bug which has been fixed in 5.4.14. Current is 5.4.22,
as of today.

-h

Re: scrub resume after suspend not working

[Robert Krig]

I'm assuming you're referring to the version of btrfs-progs and not the
kernel, right?

Am Montag, den 24.02.2020, 11:08 +0100 schrieb Holger Hoffstätte:
> It *was* a bug which has been fixed in 5.4.14. Current is 5.4.22,

Re: scrub resume after suspend not working

[Holger Hoffstätte]

On 2/24/20 2:47 PM, Robert Krig wrote:
> I'm assuming you're referring to the version of btrfs-progs and not the
> kernel, right?

I honestly don't know what lead you to this assumption, there is no
btrfs-progs release 5.4.14, let alone .22. You can find details in:
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.14
when searching for "cef6f2aeda".

-h

Re: scrub resume after suspend not working

[Robert Krig]

Woops, my bad. 

Thanks for your help.


Am Montag, den 24.02.2020, 15:47 +0100 schrieb Holger Hoffstätte:
> On 2/24/20 2:47 PM, Robert Krig wrote:
> > I'm assuming you're referring to the version of btrfs-progs and not
> > the
> > kernel, right?
> 
> I honestly don't know what lead you to this assumption, there is no
> btrfs-progs release 5.4.14, let alone .22. You can find details in:
> https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.14
> when searching for "cef6f2aeda".
> 
> -h

Re: scrub resume after suspend not working

[Robert Krig]

Ok, I've updated my kernel to upstream Kernel 5.5.
Btrfs scrub status does indeed show some stats after waking up from
suspend.

BUT,

it seems that "Bytes scrubbed" no longer increases. 
The time left and duration is stuck and doesn't change. From what I can
tell, the only value that is changing is the ETA.

This is on a BTRFS RAID10 by the way.

Is this a different bug?