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From: Avi Kivity <avi@redhat.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Kevin Wolf <kwolf@redhat.com>,
	Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>,
	Stefan Hajnoczi <stefanha@gmail.com>,
	Alexander Graf <agraf@suse.de>,
	qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [RFC] qed: Add QEMU Enhanced Disk format
Date: Thu, 09 Sep 2010 09:24:26 +0300	[thread overview]
Message-ID: <4C887D9A.3020702@redhat.com> (raw)
In-Reply-To: <20100909023550.GA19336@lst.de>

  On 09/09/2010 05:35 AM, Christoph Hellwig wrote:
> On Wed, Sep 08, 2010 at 03:28:50PM -0500, Anthony Liguori wrote:
>> That's a good point.  Is there a reasonable way to do this cooperatively
>> with the underlying filesystem?
> The only thing we can do easily is to try to use as large as possible
> extents in the allocation.  Once we're at a cuple Megabytes the
> fragmentation doesn't matter too much.

That only works if the initial write writes the entire extent 
(zero-filling a shorter write).  But that both slows down that write, 
and quickly grows the image to its full logical size.

The other thing we can do is defragment the logical image, then 
defragment the underlying file (if the filesystem supports it, issue the 
appropriate ioctl, otherwise defragment to a new file which you write 
linearly).

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

  reply	other threads:[~2010-09-09  6:34 UTC|newest]

Thread overview: 132+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-06 10:04 [Qemu-devel] [RFC] qed: Add QEMU Enhanced Disk format Stefan Hajnoczi
2010-09-06 10:25 ` Alexander Graf
2010-09-06 10:31   ` Stefan Hajnoczi
2010-09-06 14:21   ` Luca Tettamanti
2010-09-06 14:24     ` Alexander Graf
2010-09-06 16:27       ` Anthony Liguori
2010-09-06 10:27 ` [Qemu-devel] " Kevin Wolf
2010-09-06 12:40   ` Stefan Hajnoczi
2010-09-06 12:57     ` Anthony Liguori
2010-09-06 13:02       ` Stefan Hajnoczi
2010-09-06 14:10       ` Kevin Wolf
2010-09-06 16:45         ` Anthony Liguori
2010-09-06 12:45   ` Anthony Liguori
2010-09-10 23:49     ` H. Peter Anvin
2010-09-06 11:18 ` [Qemu-devel] " Daniel P. Berrange
2010-09-06 12:52   ` Anthony Liguori
2010-09-06 13:35     ` Daniel P. Berrange
2010-09-06 16:38       ` Anthony Liguori
2010-09-06 13:06 ` Anthony Liguori
2010-09-07 14:51   ` Avi Kivity
2010-09-07 15:40     ` Anthony Liguori
2010-09-07 16:09       ` Avi Kivity
2010-09-07 16:25         ` Anthony Liguori
2010-09-07 22:27           ` Anthony Liguori
2010-09-08  8:23             ` Avi Kivity
2010-09-08  8:41               ` Alexander Graf
2010-09-08  8:53                 ` Avi Kivity
2010-09-08 11:15                   ` Stefan Hajnoczi
2010-09-08 15:38                     ` Christoph Hellwig
2010-09-08 16:30                       ` Anthony Liguori
2010-09-08 20:23                         ` Christoph Hellwig
2010-09-08 20:28                           ` Anthony Liguori
2010-09-09  2:35                             ` Christoph Hellwig
2010-09-09  6:24                               ` Avi Kivity [this message]
2010-09-09 21:01                                 ` Christoph Hellwig
2010-09-10 11:15                                   ` Avi Kivity
2010-09-09  6:53                     ` Avi Kivity
2010-09-10 21:22                     ` Jamie Lokier
2010-09-14 10:46                       ` Stefan Hajnoczi
2010-09-14 11:08                         ` Stefan Hajnoczi
2010-09-14 12:54                         ` Anthony Liguori
2010-09-08 12:55                   ` Anthony Liguori
2010-09-09  6:30                     ` Avi Kivity
2010-09-08 12:48               ` Anthony Liguori
2010-09-08 13:20                 ` Kevin Wolf
2010-09-08 13:26                   ` Anthony Liguori
2010-09-08 13:46                     ` Kevin Wolf
2010-09-09  6:45                 ` Avi Kivity
2010-09-09  6:48                   ` Avi Kivity
2010-09-09 12:49                   ` Anthony Liguori
2010-09-09 16:48                     ` [Qemu-devel] " Paolo Bonzini
2010-09-09 17:02                       ` Anthony Liguori
2010-09-09 20:56                         ` Christoph Hellwig
2010-09-10 10:53                         ` Avi Kivity
2010-09-10 11:14                     ` [Qemu-devel] " Avi Kivity
2010-09-10 11:25                       ` Avi Kivity
2010-09-10 11:33                         ` Stefan Hajnoczi
2010-09-10 11:43                           ` Avi Kivity
2010-09-10 13:22                             ` Anthony Liguori
2010-09-10 13:48                               ` Christoph Hellwig
2010-09-10 15:02                                 ` Anthony Liguori
2010-09-10 15:18                                   ` Kevin Wolf
2010-09-10 15:53                                     ` Anthony Liguori
2010-09-10 16:05                                       ` Kevin Wolf
2010-09-10 17:10                                         ` Anthony Liguori
2010-09-10 17:44                                           ` Kevin Wolf
2010-09-10 17:46                                           ` Miguel Di Ciurcio Filho
2010-09-10 14:02                               ` Avi Kivity
2010-09-10 13:47                           ` Christoph Hellwig
2010-09-10 14:05                             ` Avi Kivity
2010-09-10 14:12                               ` Christoph Hellwig
2010-09-10 14:24                                 ` Avi Kivity
2010-09-10 13:16                         ` Anthony Liguori
2010-09-10 14:06                           ` Avi Kivity
2010-09-10 11:43                       ` Stefan Hajnoczi
2010-09-10 12:06                         ` Avi Kivity
2010-09-10 13:28                           ` Anthony Liguori
2010-09-10 12:12                         ` Kevin Wolf
2010-09-10 12:35                           ` Stefan Hajnoczi
2010-09-10 12:47                             ` Avi Kivity
2010-09-10 13:10                               ` Stefan Hajnoczi
2010-09-10 13:19                                 ` Avi Kivity
2010-09-10 13:39                               ` Anthony Liguori
2010-09-10 13:52                                 ` Christoph Hellwig
2010-09-10 13:56                                 ` Avi Kivity
2010-09-10 13:48                             ` Kevin Wolf
2010-09-10 13:14                       ` Anthony Liguori
2010-09-10 13:47                         ` Avi Kivity
2010-09-10 14:56                           ` Anthony Liguori
2010-09-10 15:49                             ` Avi Kivity
2010-09-10 17:07                               ` Anthony Liguori
2010-09-10 17:42                                 ` Kevin Wolf
2010-09-10 19:33                                   ` Anthony Liguori
2010-09-13 10:41                                     ` Kevin Wolf
2010-09-12 13:24                                 ` Avi Kivity
2010-09-12 15:13                                   ` Anthony Liguori
2010-09-12 15:56                                     ` Avi Kivity
2010-09-12 17:09                                       ` Anthony Liguori
2010-09-12 17:51                                         ` Avi Kivity
2010-09-12 20:18                                           ` Anthony Liguori
2010-09-13  9:24                                             ` Avi Kivity
2010-09-13 11:28                                         ` Kevin Wolf
2010-09-13 11:34                                           ` Avi Kivity
2010-09-13 11:48                                             ` Kevin Wolf
2010-09-13 13:19                                               ` Anthony Liguori
2010-09-13 13:12                                           ` Anthony Liguori
2010-09-13 11:03                                       ` Kevin Wolf
2010-09-13 13:07                                         ` Anthony Liguori
2010-09-13 13:24                                           ` Kevin Wolf
2010-09-07 16:12     ` Anthony Liguori
2010-09-07 21:35       ` Christoph Hellwig
2010-09-07 22:29         ` Anthony Liguori
2010-09-07 22:40           ` Christoph Hellwig
2010-09-08 15:07     ` Stefan Hajnoczi
2010-09-09  6:59       ` Avi Kivity
2010-09-09 17:43         ` Anthony Liguori
2010-09-09 20:46           ` Christoph Hellwig
2010-09-10 11:22           ` Avi Kivity
2010-09-10 11:29             ` Stefan Hajnoczi
2010-09-10 11:37               ` Avi Kivity
2010-09-07 13:58 ` Avi Kivity
2010-09-07 19:25 ` Blue Swirl
2010-09-07 20:41   ` Anthony Liguori
2010-09-08  7:48     ` Kevin Wolf
2010-09-08 15:37   ` Stefan Hajnoczi
2010-09-08 18:24     ` Blue Swirl
2010-09-08 18:35       ` Anthony Liguori
2010-09-08 18:56         ` Blue Swirl
2010-09-08 19:19           ` Anthony Liguori
2010-09-15 21:01 ` [Qemu-devel] " Michael S. Tsirkin
2010-09-15 21:12   ` Anthony Liguori
  -- strict thread matches above, loose matches on Subject: below --
2010-09-17  3:51 [Qemu-devel] " Khoa Huynh

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