From: Kevin Wolf <kwolf@redhat.com>
To: Philipp Hahn <hahn@univention.de>
Cc: qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] backing file support for vpc/vhd ?
Date: Wed, 19 Jun 2013 17:15:52 +0200 [thread overview]
Message-ID: <20130619151552.GL2934@dhcp-200-207.str.redhat.com> (raw)
In-Reply-To: <201306191602.02983.hahn@univention.de>
Am 19.06.2013 um 16:02 hat Philipp Hahn geschrieben:
> Hello,
>
> while working on a Xen-VM I noticed that qemu-img does not support the backing file mechanism of vpc/vhd files, but Xens blktap2 does; it has a libvhd and some tools to create and modify vpc/vhd files:
> [...]
>
> Is the lack of support for backing files in vpc/vjd in qemu just a question of time / interest, are there technical problems, or are there some political issues?
Nobody wrote the code, that's all.
Read-only support should be almost trivial, and for read-write we'd have
to add some real code to deal with the block bitmaps (without backing
files we get away with what is mostly a slow fake implementation).
Kevin
prev parent reply other threads:[~2013-06-19 15:16 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-19 14:02 [Qemu-devel] backing file support for vpc/vhd ? Philipp Hahn
2013-06-19 15:15 ` Kevin Wolf [this message]
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