From: Paolo Bonzini <pbonzini@redhat.com>
To: Zhang Haoyu <zhanghy@sangfor.com.cn>, qemu-devel <qemu-devel@nongnu.org>
Cc: Gleb Natapov <gleb@kernel.org>, Kevin Wolf <kwolf@redhat.com>,
Peter Lieven <pl@kamp.de>, Stefan Hajnoczi <stefanha@redhat.com>
Subject: Re: [Qemu-devel] question about live migration with storage
Date: Wed, 25 Mar 2015 14:07:50 +0100 [thread overview]
Message-ID: <5512B326.9030007@redhat.com> (raw)
In-Reply-To: <201503101001341072349@sangfor.com.cn>
On 10/03/2015 03:01, Zhang Haoyu wrote:
> My test results show that when using thin-provisioning qcow2
> image(created by qemu-img create -f qcow2 preallocation=metadata),
> even the unallocated sectors will be transferred to destination, so
> much data is transferred, so the qcow2 image in destination is full
> allocated.
Yes, metadata preallocation actually allocates all sectors. Only, the
qcow2 image is sparse so the sectors do not consume space on the source.
I think you can avoid the problem by passing file.detect-zeroes=unmap in
the -drive option of the destination QEMU. Kevin/Peter, can you confirm
this should work?
Paolo
prev parent reply other threads:[~2015-03-25 13:08 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-13 1:48 [Qemu-devel] question about live migration with storage Zhang Haoyu
2015-01-13 2:03 ` Zhang Haoyu
2015-01-13 9:45 ` Paolo Bonzini
2015-01-14 2:41 ` Zhang Haoyu
2015-01-14 7:34 ` Paolo Bonzini
2015-01-14 7:58 ` Zhang Haoyu
2015-01-14 9:06 ` Paolo Bonzini
2015-01-15 3:54 ` Zhang Haoyu
2015-01-15 9:11 ` Paolo Bonzini
2015-01-15 9:56 ` Zhang Haoyu
2015-01-15 10:08 ` Paolo Bonzini
2015-03-10 2:01 ` Zhang Haoyu
2015-03-25 13:07 ` Paolo Bonzini [this message]
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