From: Roman Mamedov <rm@romanrm.net>
To: CoolCold <coolthecold@gmail.com>
Cc: Linux RAID <linux-raid@vger.kernel.org>
Subject: Re: raid10, far layout initial sync slow + XFS question
Date: Sat, 2 Sep 2023 02:00:48 +0500 [thread overview]
Message-ID: <20230902020048.356667d4@nvm> (raw)
In-Reply-To: <CAGqmV7reuaeGNY3jz-8BjrmwTR3kmNzCXEa7JxouZ8v7t9QqnA@mail.gmail.com>
On Sat, 2 Sep 2023 03:43:42 +0700
CoolCold <coolthecold@gmail.com> wrote:
> > > md3 : active raid10 nvme5n1[3] nvme3n1[2] nvme4n1[1] nvme0n1[0]
> > > 7501212288 blocks super 1.2 16K chunks 2 far-copies [4/4] [UUUU]
> > > [=>...................] resync = 6.2% (466905632/7501212288)
> > > finish=207.7min speed=564418K/sec
> >
> > Any difference if you use e.g. --chunk=1024?
> Goes up to 1.4GB
>
> md3 : active raid10 nvme5n1[3] nvme3n1[2] nvme4n1[1] nvme0n1[0]
> 7501209600 blocks super 1.2 1024K chunks 2 far-copies [4/4] [UUUU]
> [>....................] resync = 0.4% (35959488/7501209600)
> finish=86.4min speed=1438382K/sec
Looks like you have found at least some bottleneck. Does it ever reach the
RAID1 performance at some point if you raise it further to 4096, 8192 or more?
It might also be worth it to try making the RAID with --assume-clean, and then
look at the actual array performance, not just the sync speed.
> > How about a newer kernel (such as 6.1)?
> Not applicable in my case- there is no test machine unluckily to play
> around with non LTS and reboots. Upgrading to next HWE kernel may
> happen though, which is 5.15.0-82-generic #91-Ubuntu.
> Do you know any specific patches/fixes landed since 5.4?
No idea. I guessed if you are just setting up a new server, it would be
possible to slip in a reboot or a few. :)
--
With respect,
Roman
next prev parent reply other threads:[~2023-09-01 21:01 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-01 20:23 raid10, far layout initial sync slow + XFS question CoolCold
2023-09-01 20:37 ` Roman Mamedov
2023-09-01 20:43 ` CoolCold
2023-09-01 21:00 ` Roman Mamedov [this message]
2023-09-01 21:17 ` CoolCold
2023-09-01 21:26 ` Roman Mamedov
2023-09-01 20:58 ` CoolCold
2023-09-02 3:56 ` Yu Kuai
2023-09-02 6:07 ` CoolCold
2023-09-02 6:13 ` Yu Kuai
2023-09-02 6:39 ` CoolCold
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