Re: shall distros run btrfsck on boot?

[Eric Sandeen <sandeen@redhat.com>]

On 11/23/15 10:35 PM, Duncan wrote:
> Christoph Anton Mitterer posted on Tue, 24 Nov 2015 05:02:34 +0100 as
> excerpted:
> 
>> Hey.
>>
>> Short question since that came up on debian-devel.
>>
>> Now that btrfs check get's more and more useful, are the developers
>> going to recommend running it periodically on boot (of course that
>> wouldn't work right now, as it would *always* check)?
> 
> I'm a list regular and btrfs user, not a dev, but all the indications 
> continue to point to _not_ running it automatically at boot, nobody even 
> _suggesting_ otherwise.  The btrfs kernel code itself detects and often 
> corrects many problems, and btrfs check is simply not recommended for 
> automatic at-boot scheduling -- if the kernel code can't fix it without 
> intervention, then the problem is too serious to be fixed without 
> intervention by some scheduled btrfs check run, as well.
> 
> In fact, take a look at the shipped fsck.btrfs shell-script, based upon 
> the xfs one.

FWIW, fsck.xfs is a no-op because xfs is a *journaling filesystem* and an
unclean shutdown is not a reason to force a filesystem repair on the next
boot.

...that's what the journal was for...!  The filesystem should be 100%
consistent after a mount & a log replay.

The only reason fsck.xfs came into existence was to satisfy initscripts,
IIRC.

-Eric