From: Paolo Bonzini <pbonzini@redhat.com>
To: John Snow <jsnow@redhat.com>, qemu-block@nongnu.org
Cc: kwolf@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com
Subject: Re: [Qemu-devel] [PATCH 1/3] block: prohibit migration during BlockJobs
Date: Thu, 1 Oct 2015 20:03:58 +0200 [thread overview]
Message-ID: <560D758E.7020309@redhat.com> (raw)
In-Reply-To: <1443717273-5280-2-git-send-email-jsnow@redhat.com>
On 01/10/2015 18:34, John Snow wrote:
> Unless we can prove this to be safe for specific cases,
> the default should be to prohibit migration during BlockJobs.
Block jobs do not affect the current block, only other block device,
hence they *are* safe for migration.
What you want, I think, is the target not to be garbage when migration
ends. Based on this you can block specific cases, namely mirror which
you already do allow (patch 2) and backup except for sync='none'.
Paolo
> In conjunction with
> "migration: disallow_migrate_add_blocker during migration",
> this should be sufficient to disallow the blockjob from starting
> in the event of an in-progress migration.
next prev parent reply other threads:[~2015-10-01 18:04 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-01 16:34 [Qemu-devel] [PATCH 0/3] block: prohibit migrations during tasks John Snow
2015-10-01 16:34 ` [Qemu-devel] [PATCH 1/3] block: prohibit migration during BlockJobs John Snow
2015-10-01 18:03 ` Paolo Bonzini [this message]
2015-10-02 18:17 ` John Snow
2015-10-05 8:13 ` Kevin Wolf
2015-10-05 14:55 ` Paolo Bonzini
2015-10-01 16:34 ` [Qemu-devel] [PATCH 2/3] block/mirror: allow migration after sync John Snow
2015-10-01 16:34 ` [Qemu-devel] [PATCH 3/3] block: prohibit migration during transactions John Snow
2015-10-01 18:01 ` Paolo Bonzini
2015-10-02 18:20 ` John Snow
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