[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support f
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support for replication] |
Date: |
Fri, 25 May 2012 13:17:04 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 |
Il 25/05/2012 11:43, Stefan Hajnoczi ha scritto:
> On Thu, May 24, 2012 at 03:41:29PM +0200, Paolo Bonzini wrote:
>> Persistent dirty bitmap
>> =======================
>>
>> A persistent dirty bitmap can be used by management for two reasons.
>> When mirroring is used for continuous replication of storage, to record
>> I/O operations that happened while the replication server is not
>> connected or unavailable.
>
> For incremental backups we also need a dirty bitmap API. This allows
> backup software to determine which blocks are "dirty" in a snapshot.
> The backup software will only copy out the dirty blocks.
>
> (For external snapshots the "dirty bitmap" is actually the qemu-io -c
> map of is_allocated clusters. But for internal snapshots it would be a
> diff of image metadata which results in a real bitmap.)
Perhaps that be simply a new qemu-img subcommand? It should be possible
to run it while the VM is offline. Then the file that is produced could
be fed to blockdev-dirty-enable.
Paolo
> So it seems like a dirty bitmap API will be required for continuous
> replication (so the server can find out what it missed) and for
> incremental backup. If there is commonality here we should work
> together so the same API can do both.
>
> Stefan
>
- Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support for replication], (continued)
- Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support for replication], Geert Jansen, 2012/05/29
- Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support for replication], Paolo Bonzini, 2012/05/29
- Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support for replication], Geert Jansen, 2012/05/30
- Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support for replication], Paolo Bonzini, 2012/05/30
Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support for replication], Eric Blake, 2012/05/24
Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support for replication], Stefan Hajnoczi, 2012/05/25
Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support for replication], Stefan Hajnoczi, 2012/05/25
- Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support for replication],
Paolo Bonzini <=
- Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support for replication], Stefan Hajnoczi, 2012/05/25
- Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support for replication], Paolo Bonzini, 2012/05/25
- Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support for replication], ronnie sahlberg, 2012/05/31
Re: [Qemu-devel] Block job commands in QEMU 1.2 [v2, including support for replication], Luiz Capitulino, 2012/05/25