From: Avi Kivity <avi@redhat.com>
To: Anthony Liguori <anthony@codemonkey.ws>
Cc: kwolf@redhat.com, hch@lst.de, Alexander Graf <agraf@suse.de>,
qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] Re: [PATCH] Add cache=volatile parameter to -drive
Date: Wed, 26 May 2010 18:13:17 +0300 [thread overview]
Message-ID: <4BFD3A8D.20006@redhat.com> (raw)
In-Reply-To: <4BFD2730.8000006@codemonkey.ws>
On 05/26/2010 04:50 PM, Anthony Liguori wrote:
>> In fact, btrfs is currently unusable for virt because O_SYNC writes
>> inflate a guest write to a host write. by a huge factor (50x-100x).
>> cache=writethrough is 100% unusable, cache=writeback is barely
>> tolerable. As of 2.6.32, cache=volatile is probably required to get
>> something resembling reasonable performance on btrfs.
>>
>> Of course, we expect that btrfs will improve in time, but still it
>> doesn't seem to be fsync friendly.
>
>
> So you're suggesting that anyone who uses virt on btrfs should be
> prepared to deal with data corruption on host failure?
No.
> That sounds to me like btrfs isn't ready for real workloads.
The btrfs developers aren't saying anything different. But people still
want to try it out (to wire up snapshotting to management, for example).
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2010-05-26 15:13 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-17 10:14 [Qemu-devel] [PATCH] Add cache=volatile parameter to -drive Alexander Graf
2010-05-17 10:42 ` [Qemu-devel] " Kevin Wolf
2010-05-17 12:58 ` Anthony Liguori
2010-05-17 13:02 ` Alexander Graf
2010-05-17 13:09 ` Anthony Liguori
2010-05-17 13:17 ` Alexander Graf
2010-05-17 13:26 ` Anthony Liguori
2010-05-17 14:04 ` Alexander Graf
2010-05-17 14:22 ` Alexander Graf
2010-05-17 15:16 ` Anthony Liguori
2010-05-17 16:23 ` Paul Brook
2010-05-17 16:26 ` Anthony Liguori
2010-05-17 16:28 ` Alexander Graf
2010-05-17 20:07 ` Jamie Lokier
2010-05-18 7:42 ` Kevin Wolf
2010-05-25 17:59 ` Alexander Graf
2010-05-25 18:48 ` Anthony Liguori
2010-05-25 19:01 ` Alexander Graf
2010-05-26 13:09 ` Avi Kivity
2010-05-25 21:01 ` Aurelien Jarno
2010-05-26 1:31 ` Anthony Liguori
2010-05-26 8:43 ` Kevin Wolf
2010-05-26 13:42 ` Anthony Liguori
2010-05-26 14:03 ` Kevin Wolf
2010-05-26 14:08 ` Anthony Liguori
2010-05-26 14:26 ` Kevin Wolf
2010-05-26 14:13 ` Aurelien Jarno
2010-05-26 8:52 ` Aurelien Jarno
2010-05-26 9:16 ` Kevin Wolf
2010-05-26 13:48 ` Anthony Liguori
2010-05-26 14:12 ` Aurelien Jarno
2010-05-26 14:19 ` Anthony Liguori
2010-05-26 15:40 ` Aurelien Jarno
2010-05-26 16:11 ` Anthony Liguori
2010-05-26 14:27 ` Paolo Bonzini
2010-05-26 13:06 ` Avi Kivity
2010-05-26 13:50 ` Anthony Liguori
2010-05-26 15:13 ` Avi Kivity [this message]
2010-05-17 15:11 ` Anthony Liguori
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