From: Dave Chinner <david@fromorbit.com>
To: baotiao <baotiao@gmail.com>
Cc: xfs@oss.sgi.com
Subject: Re: XFS: possible memory allocation deadlock in kmem_alloc
Date: Mon, 30 May 2016 15:04:52 +1000 [thread overview]
Message-ID: <20160530050452.GM26977@dastard> (raw)
In-Reply-To: <AD1240BA-DB24-44F2-893D-28A824063F99@gmail.com>
On Mon, May 30, 2016 at 12:45:07PM +0800, baotiao wrote:
> This machine is running for qemu, the file is qemu qcow file type
>
> [root@w-openstack20 /data/nova/instances/7898b630-c4ef-49ab-9ce9-3735e090c282]# file disk
> disk: QEMU QCOW Image (v3), has backing file (path /data/nova/instances/_base/3f27393376152ac352b2d85703011e38517e), 429496729600 bytes
Oh, you're using delta/snapshot based qcow images. That, by it's
very nature, generates fragmented image files as they are a delta
over the backing file.
....
> actual 48421430, ideal 20716, fragmentation factor 99.96%
>
> How can I solve this problem, what do you suggest me to do?
Use a extent size hint (say 1-8MB) for your qcow2 image files so that
they don't fragment badly as they are written to.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
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next prev parent reply other threads:[~2016-05-30 5:05 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-30 4:45 XFS: possible memory allocation deadlock in kmem_alloc baotiao
2016-05-30 5:04 ` Dave Chinner [this message]
2016-05-30 8:48 ` baotiao
2016-05-30 9:20 ` Carlos Maiolino
2016-05-31 2:43 ` 陈宗志
2016-05-31 3:10 ` Dave Chinner
2016-05-31 11:00 ` 陈宗志
2016-05-31 12:14 ` Carlos Maiolino
-- strict thread matches above, loose matches on Subject: below --
2019-11-04 23:38 Chris Holcombe
2019-11-05 0:01 ` Darrick J. Wong
2019-11-05 0:31 ` Eric Sandeen
[not found] ` <CAC752AmahECFry9x=pvqDkwQUj1PEJjoWGa2KFG1uaTzT1Bbnw@mail.gmail.com>
2019-11-05 4:21 ` Eric Sandeen
2019-11-05 16:25 ` Chris Holcombe
2019-11-05 17:11 ` Eric Sandeen
2019-11-05 19:53 ` Chris Holcombe
2019-11-05 20:08 ` Eric Sandeen
[not found] ` <CAC752AnZ4biDGk6V17URQm5YVp=MwZBhiMH8=t733zaypxUsmA@mail.gmail.com>
2019-11-05 20:47 ` Eric Sandeen
[not found] ` <CAC752A=y9PMEQ1e4mXskha1GFeKXWi8PsdBW-nX40pgFCYp1Uw@mail.gmail.com>
2019-11-05 21:23 ` Eric Sandeen
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