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Date: Tue, 28 Jul 2009 11:11:17 +0200
From: Kevin Wolf <kwolf@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH] Add new block driver for the VDI format
	(use aio)
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To: Jamie Lokier <jamie@shareable.org>
Cc: Amit Shah <amit.shah@redhat.com>, QEMU Developers <qemu-devel@nongnu.org>, Christoph Hellwig <hch@lst.de>

Jamie Lokier schrieb:
> Daniel P. Berrange wrote:
>>> By the way, why is fallocate() support being added to libvirt to
>>> improve disk image creation, instead of to qemu-img?
>> libvirt has to work with more than just QEMU.  Thus it has a built in
>> support for creating raw files, and this is where we added fallocate
>> support. It also has ability to call out to hypervisor specific tools
>> for creating non-raw formats. We support qemu-img, and qcow-create (the
>> latter from Xen)
> 
> Ok.  It sounds like fallocate() support would be useful for qemu-img
> too (even if libvirt is used to manage it, if it didn't produce it).

I agree, fallocate seems to be the right way to implement my suggestion
of a generic preallocate option in qemu-img. It's on my list, so I'm
going to work on it when I come back from vacation in two weeks.

Kevin