From: Anssi Hannula <anssi.hannula@iki.fi>
To: device-mapper development <dm-devel@redhat.com>
Subject: Re: System freeze for few seconds when using dm-cache on high load
Date: Sun, 22 Feb 2015 23:39:22 +0200 [thread overview]
Message-ID: <54EA4C8A.8010502@iki.fi> (raw)
In-Reply-To: <54B6626E.8020606@gmail.com>
Hi,
14.01.2015, 14:34, Michał Zubkowicz kirjoitti:
> I'm using dm-cache on such setup:
> dm-cache -> luks -> lvm2 ->ext4
> Kernel version: 3.13.0-43
>
> On high disk load (ie when saving virtual machine state) whole system
> freezes for a few seconds.
> I've tried already to change scheduler (from deadline to cbq), change
> ext4 mount options, now i've got:
> errors=remount-ro,noatime,nodiratime,discard,barrier=0,relatime
>
> There is something I should check, or maybe it's a 'normal' behaviour,
> or maybe my whole setup is wrong?
>
Can't really help you directly, but just for the record, I also get
whole-system (i.e. not just frozen disks) freezes of 10-60 seconds on
heavy disk load on a somewhat similar system:
kernel 3.14.27,
md-raid6 (16x 4TB) -> lvm with lvm-cache (dm-cache) -> luks -> ext4.
Haven't had the time to investigate further, and they are still rather
rare for me (~1 per month).
They seemed to start when I added dm-cache and luks to the setup.
No messages appear in kernel log when it happens.
--
Anssi Hannula
--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel
prev parent reply other threads:[~2015-02-22 21:39 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-14 12:34 System freeze for few seconds when using dm-cache on high load Michał Zubkowicz
2015-02-22 21:39 ` Anssi Hannula [this message]
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