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From: Stefan Hajnoczi <stefanha@gmail.com>
To: Dietmar Maurer <dietmar@proxmox.com>
Cc: Kevin Wolf <kwolf@redhat.com>,
	"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
	qemu-block@nongnu.org, Max Reitz <mreitz@redhat.com>
Subject: Re: backup_calculate_cluster_size does not consider source
Date: Wed, 6 Nov 2019 09:32:22 +0100	[thread overview]
Message-ID: <20191106083222.GA189998@stefanha-x1.localdomain> (raw)
In-Reply-To: <1767781109.66.1572948164492@webmail.proxmox.com>

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On Tue, Nov 05, 2019 at 11:02:44AM +0100, Dietmar Maurer wrote:
> Example: Backup from ceph disk (rbd_cache=false) to local disk:
> 
> backup_calculate_cluster_size returns 64K (correct for my local .raw image)
> 
> Then the backup job starts to read 64K blocks from ceph.
> 
> But ceph always reads 4M block, so this is incredibly slow and produces
> way too much network traffic.
> 
> Why does backup_calculate_cluster_size does not consider the block size from
> the source disk? 
> 
> cluster_size = MAX(block_size_source, block_size_target)

CCing block maintainers so they see your email and you get a response
more quickly.

Stefan

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  reply	other threads:[~2019-11-06  8:33 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-05 10:02 backup_calculate_cluster_size does not consider source Dietmar Maurer
2019-11-06  8:32 ` Stefan Hajnoczi [this message]
2019-11-06  9:37   ` Max Reitz
2019-11-06 10:18     ` Dietmar Maurer
2019-11-06 10:37       ` Max Reitz
2019-11-06 10:34     ` Wolfgang Bumiller
2019-11-06 10:42       ` Max Reitz
2019-11-06 11:18         ` Dietmar Maurer
2019-11-06 11:22           ` Max Reitz
2019-11-06 11:37             ` Max Reitz
2019-11-06 13:09               ` Dietmar Maurer
2019-11-06 13:17                 ` Max Reitz
2019-11-06 13:34                   ` Dietmar Maurer
2019-11-06 13:52                     ` Max Reitz
2019-11-06 14:39                       ` Vladimir Sementsov-Ogievskiy

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