Permanent uncancellable balance

Permanent uncancellable balance

[Gabriel de Perthuis]

Hello,
I have a filesystem that has become unusable because of a balance I can't 
stop. It is very close to full, and the balance is preventing me from 
growing it.

It was started like this:
sudo btrfs filesystem balance start -v -musage=60 -dusage=60 /srv/backups

It has been stuck at 0% across reboots and kernel upgrades (currently on 
3.8.1), and cancelling it had no effect:

Balance on '/srv/backups' is running
0 out of about 5 chunks balanced (95 considered), 100% left

According to atop it is writing but not reading anything.
Unmounting never terminates, so does remounting ro, the only way to 
temporarilly kill it is to reboot. SIGKILL has no effect either. Is there 
*any* way I can get rid of it?

Re: Permanent uncancellable balance

[Roman Mamedov]

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On Sat, 2 Mar 2013 10:07:45 +0000 (UTC)
Gabriel de Perthuis <g2p.code@gmail.com> wrote:

> Hello,
> I have a filesystem that has become unusable because of a balance I can't 
> stop. It is very close to full, and the balance is preventing me from 
> growing it.
> 
> It was started like this:
> sudo btrfs filesystem balance start -v -musage=60 -dusage=60 /srv/backups
> 
> It has been stuck at 0% across reboots and kernel upgrades (currently on 
> 3.8.1), and cancelling it had no effect:
> 
> Balance on '/srv/backups' is running
> 0 out of about 5 chunks balanced (95 considered), 100% left
> 
> According to atop it is writing but not reading anything.
> Unmounting never terminates, so does remounting ro, the only way to 
> temporarilly kill it is to reboot. SIGKILL has no effect either. Is there 
> *any* way I can get rid of it?
> 
> --
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Mount with the "skip_balance" option
https://btrfs.wiki.kernel.org/index.php/Mount_options
then you can issue "btrfs fi balance cancel" and it will succeed.

-- 
With respect,
Roman

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Re: Permanent uncancellable balance

[Gabriel de Perthuis]

On Sat, 02 Mar 2013 17:12:37 +0600, Roman Mamedov wrote:
> Mount with the "skip_balance" option
> https://btrfs.wiki.kernel.org/index.php/Mount_options then you can issue
> "btrfs fi balance cancel" and it will succeed.

Excellent, thank you.
I had just thought of doing the same thing with ro and it worked.