[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] Re: [PATCH 1/3] block: allow migration to work with image f
From: |
Juan Quintela |
Subject: |
[Qemu-devel] Re: [PATCH 1/3] block: allow migration to work with image files |
Date: |
Wed, 15 Sep 2010 17:53:13 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) |
Anthony Liguori <address@hidden> wrote:
> Image files have two types of data: immutable data that describes things like
> image size, backing files, etc. and mutable data that includes offset and
> reference count tables.
>
> Today, image formats aggressively cache mutable data to improve performance.
> In
> some cases, this happens before a guest even starts. When dealing with live
> migration, since a file is open on two machines, the caching of meta data can
> lead to data corruption.
>
> This patch addresses this by introducing a mechanism to invalidate any cached
> mutable data a block driver may have which is then used by the live migration
> code.
>
> NB, this still requires coherent shared storage. Addressing migration without
> coherent shared storage (i.e. NFS) requires additional work.
>
> Signed-off-by: Anthony Liguori <address@hidden>
For the NFS case, we just need 2 different case:
- outgoing: nothing to do (generic code already do an fsync())
- incoming: we need to reopen the image.
For the rest, I agree. Once told that, I can implement my changes here.
Later, Juan.
- Re: [Qemu-devel] [PATCH 1/3] block: allow migration to work with image files, (continued)
- Re: [Qemu-devel] [PATCH 1/3] block: allow migration to work with image files, Anthony Liguori, 2010/09/12
- Re: [Qemu-devel] [PATCH 1/3] block: allow migration to work with image files, Avi Kivity, 2010/09/12
- Re: [Qemu-devel] [PATCH 1/3] block: allow migration to work with image files, Anthony Liguori, 2010/09/12
- Re: [Qemu-devel] [PATCH 1/3] block: allow migration to work with image files, Avi Kivity, 2010/09/12
- [Qemu-devel] Re: [PATCH 1/3] block: allow migration to work with image files, Juan Quintela, 2010/09/15
- [Qemu-devel] Re: [PATCH 1/3] block: allow migration to work with image files, Juan Quintela, 2010/09/15
[Qemu-devel] Re: [PATCH 1/3] block: allow migration to work with image files, Kevin Wolf, 2010/09/13
[Qemu-devel] Re: [PATCH 1/3] block: allow migration to work with image files,
Juan Quintela <=
Re: [Qemu-devel] [RFC][PATCH 0/3] Fix caching issues with live migration, Avi Kivity, 2010/09/12