From: Peter Krempa <pkrempa@redhat.com>
To: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Cc: John Snow <jsnow@redhat.com>,
qemu-devel@nongnu.org, qemu-block@nongnu.org,
Markus Armbruster <armbru@redhat.com>
Subject: Re: [PATCH 2/2] migration: dirty-bitmap: Allow control of bitmap persistence on destination
Date: Wed, 3 Feb 2021 14:27:44 +0100 [thread overview]
Message-ID: <20210203132744.GE54538@angien.pipo.sk> (raw)
In-Reply-To: <a519d6af-7f24-e9bc-894b-070738008e01@virtuozzo.com>
On Wed, Feb 03, 2021 at 16:23:21 +0300, Vladimir Sementsov-Ogievskiy wrote:
> 03.02.2021 16:00, Peter Krempa wrote:
> > Bitmap's source persistence is transported over the migration stream and
> > the destination mirrors it. In some cases the destination might want to
> > persist bitmaps which are not persistent on the source (e.g. the result
> > of merge of bitmaps from a number of layers on the source when migrating
> > into a squashed image)
>
> Why not make merge target on source be persistent itself? Then it will be persistent on migration destination.
Because they are temporary on the source. I don't want to make it
persistent in case of a failure so that it doesn't get written to the
disk e.g. in case of VM shutdown.
>
> > but currently it would need to create another set
> > of persistent bitmaps and merge them.
> >
> > This adds 'dest-persistent' optional property to
> > 'BitmapMigrationBitmapAlias' which when present overrides the bitmap
> > presence state from the source.
>
> It's seems simpler to make a separate qmp command block-dirty-bitmap-make-persistent.. Didn't you consider this way?
I'm not sure how the internals work entirely. In my case it's way
simpler to do this setup when generating the mapping which I need to do
anyways rather than calling separate commands.
next prev parent reply other threads:[~2021-02-03 13:29 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-03 12:59 [PATCH 0/2] migration: dirty-bitmap: Allow control of bitmap persistence on destination Peter Krempa
2021-02-03 12:59 ` [PATCH 1/2] migration: dirty-bitmap: Convert alias map inner members to a struct Peter Krempa
2021-02-04 19:12 ` Eric Blake
2021-02-05 7:04 ` Vladimir Sementsov-Ogievskiy
2021-02-03 13:00 ` [PATCH 2/2] migration: dirty-bitmap: Allow control of bitmap persistence on destination Peter Krempa
2021-02-03 13:23 ` Vladimir Sementsov-Ogievskiy
2021-02-03 13:27 ` Peter Krempa [this message]
2021-02-03 13:39 ` Peter Krempa
2021-02-03 14:14 ` Vladimir Sementsov-Ogievskiy
2021-02-04 19:15 ` Eric Blake
2021-02-05 8:01 ` Vladimir Sementsov-Ogievskiy
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