lkml.org 
[lkml]   [2022]   [Dec]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [6.2][regression] after commit 947a629988f191807d2d22ba63ae18259bb645c5 btrfs volume periodical forced switch to readonly after a lot of disk writes


On 2022/12/29 08:08, Mikhail Gavrilov wrote:
> On Thu, Dec 29, 2022 at 4:31 AM Qu Wenruo <quwenruo.btrfs@gmx.com> wrote:
>>
>> Are you using qgroup? If so it may be worthy trying disabling qgroup.
>
> I do not use quota.
> And looks like my distro does not use quita by default.
> ❯ btrfs qgroup show -f /
> ERROR: can't list qgroups: quotas not enabled
>
>> But for newer kernel, qgroup hang should only happen when dropping large
>> snapshot, I don't know if podman pull would cause older snapshots to be
>> deleted...
>
> It is not a regression, it also happened on older kernels.
> But it is really annoying when the browser process waits when "podman
> pull" writes changes to disk.
> In fact, I have been waiting for 5 years for caching of slow HDDs by
> using the cache on the SSD, but apparently I can’t wait.
> And I started slowly buying expensive large SSDs to replace the big
> HDD. I still can’t find time to connect D5 P5316 30.72 Tb to the
> primary workstation.
> I want to make a video review of it. I understand this is an expensive
> solution and not suitable for everyone, unlike an affordable SDD
> cache.
>
This is really sad to hear that.

For now, I only have several guesses on how this could happen.

- Extra seeks between metadata and data chunks
You can try with mixed block groups, but this needs mkfs time tuning.

- Extra inlined extents causing too much metadata overhead
You can disable inline extents using max_inline=0 as mount options.
But that only affects newly created files, not the existing ones.

Otherwise, using bcache may be a solution.

For now I'm not aware of any HDD specific tests, other than zoned
devices, thus the performance problem can be really hard to debug.

Thanks,
Qu

\
 
 \ /
  Last update: 2023-03-26 23:22    [W:0.069 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site