From: Gionatan Danti <g.danti@assyoma.it>
To: LVM general discussion and development <linux-lvm@redhat.com>,
Daniel Janzon <daniel.janzon@edgeware.tv>
Subject: Re: [linux-lvm] Best way to run LVM over multiple SW RAIDs?
Date: Tue, 10 Dec 2019 12:23:14 +0100 [thread overview]
Message-ID: <0154b0c2-be41-cf37-0973-2ade719321cd@assyoma.it> (raw)
In-Reply-To: <A8A53B0E4B7ACF4BAD5C77D3671AC8976ABE90D8@EX01.edgeware.tv>
On 09/12/19 11:26, Daniel Janzon wrote:
> Exactly. The md driver executes on a single core, but with a bunch of RAID5s
> I can distribute the load over many cores. That's also why I cannot join the
> bunch of RAID5's with a RAID0 (as someone suggested) because then again
> all data is pulled through a single core.
MD RAID0 is extremely fast, using a single core at the striping level
should pose no problem. Did you actually tried this setup?
Anyway, the suggestion from Guoqing Jiang sound promising. Let me quote him:
> Perhaps set "/sys/block/mdx/md/group_thread_cnt" could help here,
> see below commits:
>
> commit b721420e8719131896b009b11edbbd27d9b85e98
> Author: Shaohua Li <shli@kernel.org>
> Date: Tue Aug 27 17:50:42 2013 +0800
>
> raid5: sysfs entry to control worker thread number
>
> commit 851c30c9badfc6b294c98e887624bff53644ad21
> Author: Shaohua Li <shli@kernel.org>
> Date: Wed Aug 28 14:30:16 2013 +0800
>
> raid5: offload stripe handle to workqueue
Regards.
--
Danti Gionatan
Supporto Tecnico
Assyoma S.r.l. - www.assyoma.it
email: g.danti@assyoma.it - info@assyoma.it
GPG public key ID: FF5F32A8
next prev parent reply other threads:[~2019-12-10 11:23 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-09 10:26 [linux-lvm] Best way to run LVM over multiple SW RAIDs? Daniel Janzon
2019-12-09 14:26 ` Marian Csontos
2019-12-10 11:23 ` Gionatan Danti [this message]
2019-12-10 21:29 ` John Stoffel
-- strict thread matches above, loose matches on Subject: below --
2019-12-16 8:22 Daniel Janzon
2019-10-29 8:47 Daniel Janzon
2019-12-07 16:16 ` Anatoly Pugachev
2019-12-07 17:37 ` Roberto Fastec
2019-12-07 20:34 ` Stuart D. Gathman
2019-12-07 22:44 ` John Stoffel
2019-12-07 23:14 ` Stuart D. Gathman
2019-12-08 11:57 ` Gionatan Danti
2019-12-08 22:51 ` John Stoffel
2019-12-09 10:40 ` Guoqing Jiang
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