From: Gionatan Danti <g.danti@assyoma.it>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: linux-xfs@vger.kernel.org, g.danti@assyoma.it
Subject: Re: XFS reflink vs ThinLVM
Date: Sat, 18 Jan 2020 12:08:48 +0100 [thread overview]
Message-ID: <cc3d0819966d2d3f5b8512ed0f6b1de1@assyoma.it> (raw)
In-Reply-To: <20200117234219.GM8257@magnolia>
Il 18-01-2020 00:42 Darrick J. Wong ha scritto:
> How many fragments, and how big of a sparse file?
A just installed CentOS 8 guest using a 20 GB sparse file vdisk had
about 2000 fragments.
After running "fio --name=test --filename=test.img --rw=randwrite
--size=4G" for about 30 mins, it ended with over 1M fragments/extents.
At that point, reflinking that file took over 2 mins, and unlinking it
about 4 mins.
I understand fio randwrite pattern is a worst case scenario; still, I
think the results are interesting and telling for "aged" virtual
machines.
As a side note, a just installed Win2019 guest backed with an 80 GB
sparse file had about 18000 fragments.
Thanks.
--
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:[~2020-01-18 11:08 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-13 10:22 XFS reflink vs ThinLVM Gionatan Danti
2020-01-13 11:10 ` Carlos Maiolino
2020-01-13 11:25 ` Gionatan Danti
2020-01-13 11:43 ` Carlos Maiolino
2020-01-13 12:21 ` Gionatan Danti
2020-01-13 15:34 ` Gionatan Danti
2020-01-13 16:53 ` Darrick J. Wong
2020-01-13 17:00 ` Gionatan Danti
2020-01-13 18:09 ` Darrick J. Wong
2020-01-14 8:45 ` Gionatan Danti
2020-01-15 11:37 ` Gionatan Danti
2020-01-15 16:39 ` Darrick J. Wong
2020-01-15 17:45 ` Gionatan Danti
2020-01-17 21:58 ` Gionatan Danti
2020-01-17 23:42 ` Darrick J. Wong
2020-01-18 11:08 ` Gionatan Danti [this message]
2020-01-18 23:06 ` Darrick J. Wong
2020-01-19 8:45 ` Gionatan Danti
2020-01-13 16:14 ` Chris Murphy
2020-01-13 16:25 ` Gionatan Danti
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