From: Chris Murphy <lists@colorremedies.com>
To: Supercilious Dude <supercilious.dude@gmail.com>
Cc: Chris Murphy <lists@colorremedies.com>,
Btrfs BTRFS <linux-btrfs@vger.kernel.org>,
Qu Wenruo <quwenruo.btrfs@gmx.com>
Subject: Re: MD RAID 5/6 vs BTRFS RAID 5/6
Date: Sun, 20 Oct 2019 23:43:52 +0200 [thread overview]
Message-ID: <CAJCQCtSe-H12qu6dUWfD3WJAA+i=Z-G9ZM5M_wqOBJCv0+VcvQ@mail.gmail.com> (raw)
In-Reply-To: <CAGmvKk4wENpDqLFZG+D8_zzjhXokjMfdbmgTKTL49EFcfdVEtQ@mail.gmail.com>
On Sat, Oct 19, 2019 at 12:18 AM Supercilious Dude
<supercilious.dude@gmail.com> wrote:
>
> It would be be useful to have the ability to scrub only the metadata. In many cases the data is so large that a full scrub is not feasible. In my "little" test system of 34TB a full scrub takes many hours and the IOPS saturate the disks to the extent that the volume is unusable due to the high latencies. Ideally there should be a way to rate limit the scrub operation so that it can happen in the background without impacting the normal workload.
In effect a 'btrfs check' is a read only scrub of metadata, as all
metadata is needed to be read for that. Of course it's more expensive
than just confirm checksums are OK, because it's also doing a bunch of
sanity and logical tests that take much longer.
--
Chris Murphy
prev parent reply other threads:[~2019-10-20 21:44 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-16 15:40 MD RAID 5/6 vs BTRFS RAID 5/6 Edmund Urbani
2019-10-16 19:42 ` Zygo Blaxell
2019-10-21 15:27 ` Edmund Urbani
2019-10-21 19:34 ` Zygo Blaxell
2019-10-23 16:32 ` Edmund Urbani
2019-10-26 0:01 ` Zygo Blaxell
2019-10-17 4:07 ` Jon Ander MB
2019-10-17 15:57 ` Chris Murphy
2019-10-17 18:23 ` Graham Cobb
2019-10-20 21:41 ` Chris Murphy
2019-10-18 22:19 ` Supercilious Dude
[not found] ` <CAGmvKk4wENpDqLFZG+D8_zzjhXokjMfdbmgTKTL49EFcfdVEtQ@mail.gmail.com>
2019-10-20 21:43 ` Chris Murphy [this message]
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