From: Paolo Bonzini <pbonzini@redhat.com>
To: Alexandre DERUMIER <aderumier@odiso.com>,
qemu-devel <qemu-devel@nongnu.org>
Cc: Ceph Devel <ceph-devel@vger.kernel.org>
Subject: Re: [Qemu-devel] qemu drive-mirror to rbd storage : no sparse rbd image
Date: Sun, 12 Oct 2014 15:02:12 +0200 [thread overview]
Message-ID: <543A7BD4.4030601@redhat.com> (raw)
In-Reply-To: <749ee402-bce4-45cb-97f2-8946542437fc@mailpro>
Il 08/10/2014 13:15, Alexandre DERUMIER ha scritto:
> Hi,
>
> I'm currently planning to migrate our storage to ceph/rbd through qemu drive-mirror
>
> and It seem that drive-mirror with rbd block driver, don't create a sparse image. (all zeros are copied to the target rbd).
>
> Also note, that it's working fine with "qemu-img convert" , the rbd volume is sparse after conversion.
>
>
> Could it be related to the "bdrv_co_write_zeroes" missing features in block/rbd.c ?
>
> (It's available in other block drivers (scsi,gluster,raw-aio) , and I don't have this problem with theses block drivers).
Lack of bdrv_co_write_zeroes is why detect-zeroes does not work.
Lack of bdrv_get_block_status is why sparse->sparse does not work
without detect-zeroes.
Paolo
next prev parent reply other threads:[~2014-10-12 13:02 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <54c55fc6-b12a-42e5-b99d-9752c8a9b19b@mailpro>
2014-10-08 11:15 ` [Qemu-devel] qemu drive-mirror to rbd storage : no sparse rbd image Alexandre DERUMIER
2014-10-11 7:01 ` Fam Zheng
2014-10-11 8:00 ` Alexandre DERUMIER
2014-10-11 8:25 ` Fam Zheng
2014-10-11 8:30 ` Andrey Korolyov
2014-10-12 10:02 ` Alexandre DERUMIER
2014-10-12 10:33 ` Alexandre DERUMIER
2014-10-12 13:02 ` Paolo Bonzini [this message]
2014-10-13 6:06 ` Alexandre DERUMIER
2014-10-13 7:06 ` Paolo Bonzini
2014-10-13 8:08 ` Alexandre DERUMIER
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