From: Kevin Jamieson <kjamieson@bycast.com>
To: linux-lvm@redhat.com
Subject: Re: [linux-lvm] Should I expect snapshot origin LV's to be 10x slower?
Date: Fri, 01 Jun 2007 12:37:47 -0700 [thread overview]
Message-ID: <4660758B.7010908@bycast.com> (raw)
Alex Owen wrote:
> I have been using commands of the form:
> time dd if=/dev/zero of=/dev/volgroup/test bs=1M count=100
> to get speeds for copying to a LVM device both WITH and WITHOUT a
> single snapshot.
>
> It seems that writes take >=10 times longer the first time a newly
> snapshot origin device is written to.
You may want to try the kernel patch posted here:
http://marc.info/?l=dm-devel&m=118056593528910&w=1
That change gave me a significant speedup in similar tests.
Kevin
next reply other threads:[~2007-06-01 19:37 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-01 19:37 Kevin Jamieson [this message]
-- strict thread matches above, loose matches on Subject: below --
2007-05-10 13:54 [linux-lvm] Should I expect snapshot origin LV's to be 10x slower? Alex Owen
2007-05-10 14:33 ` Greg Freemyer
2007-05-10 18:36 ` Ming Zhang
2007-05-15 19:32 ` Kottaridis, Chris
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