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Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format
From: |
Chunqiang Tang |
Subject: |
Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249% |
Date: |
Wed, 19 Jan 2011 12:08:41 -0500 |
> Actually current filesystems do pretty well on thinly provisioned
> storage, as long as your extent size is not too small. Starting from
> extent size in the 64M to 256M range there's almost no difference to
> non-virtualized storage.
>
> Again, sparse images with a large enough allocation size give you almost
> the same numbers as preallocated images. I've been doing quite a lot of
> work on TP support in QEMU. Using an XFS filesystem to back the image
> with an extent size hint in the above mentioned range gives performance
> withing 1% of fully preallocated images. With the added benefit of
> allowing to deallocate the space again through the SCSI WRITE_SAME
> or ATA TRIM commands.
These numbers are very interesting and I would like to read more. Are
your detailed results accessible on the Internet? Do you have numbers on
the impact of using a large extent size (64-256MB) on thin provisioning
(since a guest file system's metadata are written first and are scattered
in the virtual disk)?
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, (continued)
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Anthony Liguori, 2011/01/05
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Chunqiang Tang, 2011/01/14
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Jamie Lokier, 2011/01/18
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Stefan Hajnoczi, 2011/01/19
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Chunqiang Tang, 2011/01/19
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Christoph Hellwig, 2011/01/19
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Jamie Lokier, 2011/01/19
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Christoph Hellwig, 2011/01/19
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Chunqiang Tang, 2011/01/19
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Christoph Hellwig, 2011/01/19
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%,
Chunqiang Tang <=
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Christoph Hellwig, 2011/01/19
Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Stefan Hajnoczi, 2011/01/06
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Chunqiang Tang, 2011/01/14
- Message not available
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Stefan Hajnoczi, 2011/01/17
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Chunqiang Tang, 2011/01/18
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Jamie Lokier, 2011/01/18
- Re: [Qemu-devel] [RFC] Propose the Fast Virtual Disk (FVD) image format that outperforms QCOW2 by 249%, Chunqiang Tang, 2011/01/19