From: Anthony Liguori <anthony@codemonkey.ws>
To: Avi Kivity <avi@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>, Chunqiang Tang <ctang@us.ibm.com>,
qemu-devel@nongnu.org,
Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>,
Markus Armbruster <armbru@redhat.com>
Subject: Re: [Qemu-devel] Re: Strategic decision: COW format
Date: Wed, 23 Feb 2011 09:52:02 -0600 [thread overview]
Message-ID: <4D652D22.9080605@codemonkey.ws> (raw)
In-Reply-To: <4D6529A9.3090509@redhat.com>
On 02/23/2011 09:37 AM, Avi Kivity wrote:
> On 02/23/2011 05:31 PM, Anthony Liguori wrote:
>>>
>>>> what about snapshots? Are we okay having a feature in a prominent
>>>> format that isn't going to meet user's expectations?
>>>>
>>>> Is there any hope that an image with 1000, 1000, or 10000 snapshots
>>>> is going to have even reasonable performance in qcow2?
>>>>
>>>
>>> Are thousands of snapshots for a single image a reasonable user
>>> expectation? What's the use case?
>>
>>
>> Checkpointing. It was the original use-case that led to qcow2 being
>> invented.
>
> I still don't see. What would you do with thousands of checkpoints?
Er, hit send to quickly.
HPC is a big space where checkpointing is actually useful. An HPC
workload may take weeks to run to completion. If something fails during
the run, it's a huge waste of time. However, if you do regularl
checkpointing, a failure may only lose a few minutes of work instead of
the entire weeks worth of work.
Regards,
Anthony Liguori
next prev parent reply other threads:[~2011-02-23 15:51 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <OF3C9DAE9F.EC6B5878-ON85257826.00715C10-85257826.007A14FB@LocalDomain>
2011-02-15 19:45 ` [Qemu-devel] Re: Comparing New Image Formats: FVD vs. QED Chunqiang Tang
2011-02-16 12:34 ` Kevin Wolf
2011-02-17 16:04 ` Chunqiang Tang
2011-02-18 9:12 ` Strategic decision: COW format (was: [Qemu-devel] Re: Comparing New Image Formats: FVD vs. QED) Markus Armbruster
2011-02-18 9:57 ` [Qemu-devel] Re: Strategic decision: COW format Kevin Wolf
2011-02-18 14:20 ` Anthony Liguori
2011-02-22 8:37 ` Markus Armbruster
2011-02-22 8:56 ` Kevin Wolf
2011-02-22 10:21 ` Markus Armbruster
2011-02-22 15:57 ` Anthony Liguori
2011-02-22 16:15 ` Kevin Wolf
2011-02-22 18:18 ` Anthony Liguori
2011-02-23 9:13 ` Kevin Wolf
2011-02-23 14:21 ` Anthony Liguori
2011-02-23 14:55 ` Kevin Wolf
2011-02-23 13:43 ` Avi Kivity
2011-02-23 14:23 ` Anthony Liguori
2011-02-23 14:38 ` Kevin Wolf
2011-02-23 15:29 ` Anthony Liguori
2011-02-23 15:36 ` Avi Kivity
2011-02-23 15:47 ` Anthony Liguori
2011-02-23 15:59 ` Avi Kivity
2011-02-23 15:54 ` Kevin Wolf
2011-02-23 15:23 ` Avi Kivity
2011-02-23 15:31 ` Anthony Liguori
2011-02-23 15:37 ` Avi Kivity
2011-02-23 15:50 ` Anthony Liguori
2011-02-23 16:03 ` Avi Kivity
2011-02-23 16:04 ` Anthony Liguori
2011-02-23 16:15 ` Kevin Wolf
2011-02-25 11:20 ` Pavel Dovgaluk
[not found] ` <-1737654525499315352@unknownmsgid>
2011-02-25 13:22 ` Stefan Hajnoczi
2011-02-23 15:52 ` Anthony Liguori [this message]
2011-02-23 15:59 ` Gleb Natapov
2011-02-23 16:00 ` Avi Kivity
2011-02-23 15:33 ` Daniel P. Berrange
2011-02-23 15:38 ` Avi Kivity
2011-02-18 17:43 ` Stefan Weil
2011-02-18 19:11 ` Kevin Wolf
2011-02-18 19:47 ` Anthony Liguori
2011-02-18 20:49 ` Kevin Wolf
2011-02-18 20:50 ` Anthony Liguori
2011-02-18 21:27 ` Kevin Wolf
2011-02-19 17:19 ` Stefan Hajnoczi
2011-02-18 20:31 ` Anthony Liguori
2011-02-19 12:27 ` [Qemu-devel] Bugs in the VDI Block Device Driver Chunqiang Tang
2011-02-19 16:21 ` Stefan Hajnoczi
2011-02-19 18:49 ` Stefan Weil
2011-02-20 22:13 ` [Qemu-devel] Re: Strategic decision: COW format Aurelien Jarno
2011-02-21 8:59 ` Kevin Wolf
2011-02-21 13:44 ` Stefan Hajnoczi
2011-02-21 14:10 ` Kevin Wolf
2011-02-21 15:16 ` Anthony Liguori
2011-02-21 15:26 ` Kevin Wolf
2011-02-23 3:32 ` Chunqiang Tang
2011-02-23 13:20 ` Markus Armbruster
[not found] ` <OFAEB4CD91.BE989F29-ON8525783F.007366B8-85257840.00130B47@LocalDomain>
2011-03-13 5:51 ` Chunqiang Tang
2011-03-13 17:48 ` Anthony Liguori
2011-03-14 2:28 ` Chunqiang Tang
2011-03-14 13:22 ` Anthony Liguori
2011-03-14 13:53 ` Chunqiang Tang
2011-03-14 14:02 ` Anthony Liguori
2011-03-14 14:21 ` Kevin Wolf
2011-03-14 14:35 ` Chunqiang Tang
2011-03-14 14:49 ` Anthony Liguori
2011-03-14 15:05 ` Stefan Hajnoczi
2011-03-14 15:08 ` Kevin Wolf
2011-03-14 14:26 ` Stefan Hajnoczi
2011-03-14 14:30 ` Chunqiang Tang
2011-03-14 14:15 ` Kevin Wolf
2011-03-14 14:25 ` Chunqiang Tang
2011-03-14 14:31 ` Stefan Hajnoczi
2011-03-14 16:32 ` Chunqiang Tang
2011-03-14 17:57 ` Kevin Wolf
2011-03-14 19:23 ` Chunqiang Tang
2011-03-14 20:16 ` Kevin Wolf
[not found] ` <OF7C2FDD40.E76A4E14-ON85257853.005ADD68-85257853.005AF16E@LocalDomain>
2011-03-14 21:32 ` Chunqiang Tang
2011-03-14 14:34 ` Kevin Wolf
2011-03-14 14:47 ` Anthony Liguori
2011-03-14 15:03 ` Kevin Wolf
2011-03-14 15:13 ` Anthony Liguori
2011-03-14 15:04 ` Chunqiang Tang
2011-03-14 15:07 ` Stefan Hajnoczi
2011-03-14 10:12 ` Kevin Wolf
2011-02-22 8:40 ` Markus Armbruster
2011-02-16 13:21 ` [Qemu-devel] Re: Comparing New Image Formats: FVD vs. QED Stefan Hajnoczi
2011-02-17 16:04 ` Chunqiang Tang
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