All of lore.kernel.org
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: Anthony Liguori <anthony@codemonkey.ws>
Cc: Kevin Wolf <kwolf@redhat.com>,
	Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>,
	Stefan Hajnoczi <stefanha@gmail.com>,
	qemu-devel@nongnu.org, Alexander Graf <agraf@suse.de>,
	Avi Kivity <avi@redhat.com>, Christoph Hellwig <hch@lst.de>
Subject: Re: [Qemu-devel] [RFC] qed: Add QEMU Enhanced Disk format
Date: Thu, 9 Sep 2010 04:35:50 +0200	[thread overview]
Message-ID: <20100909023550.GA19336@lst.de> (raw)
In-Reply-To: <4C87F202.5000602@codemonkey.ws>

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.

> BTW, the same problem would occur for sparse file system images, no?

Sparse filesystems images are relatively probe to fragmentation, too.
Some filesystems like ext4 have heuristics that try to related physical
locality to logical locality, but that only helps if the filesystem is
relatively empty.  On XFS you can set a minimum extent size which forces
the filesystem to allocate more data than nessecary and thus reduce
fragmentation.  That's equivalent to suggestion a above to use larger
extents in the image format.

  reply	other threads:[~2010-09-09  2:36 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 [this message]
2010-09-09  6:24                               ` Avi Kivity
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20100909023550.GA19336@lst.de \
    --to=hch@lst.de \
    --cc=agraf@suse.de \
    --cc=anthony@codemonkey.ws \
    --cc=avi@redhat.com \
    --cc=kwolf@redhat.com \
    --cc=qemu-devel@nongnu.org \
    --cc=stefanha@gmail.com \
    --cc=stefanha@linux.vnet.ibm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.