|
From: | Eric Blake |
Subject: | Re: [Qemu-devel] live snapshot wiki updated |
Date: | Wed, 20 Jul 2011 07:46:58 -0600 |
User-agent: | Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.18) Gecko/20110621 Fedora/3.1.11-1.fc14 Lightning/1.0b3pre Mnenhy/0.8.3 Thunderbird/3.1.11 |
On 07/20/2011 07:25 AM, Jes Sorensen wrote:
I think if libvirt wants qemu to use an fd instead of a file name, it shouldn't pass a file name but an fd in the first place. Which means that the two that we need are support for an fd: protocol (patches on the list, need review), and a way for libvirt to override the backing file of an image.The problem is that QEMU will find backing file file names inside the images which it will be unable to open. How do you suggest we get around that?
We've already told you - qemu must have a way to be passed fds which are associated with names, and when a file refers to another backing file by name, then qemu falls back on its fd/name mapping to use the already-passed fd instead. Which implies that someone else, either libvirt or a qemu-maintained libblockformat.so, needs to have a stable interface for parsing the backing file name out of an arbitrary qcow2 file, and that this interface must work no matter how many other extensions are added to qcow2.
-- Eric Blake address@hidden +1-801-349-2682 Libvirt virtualization library http://libvirt.org
[Prev in Thread] | Current Thread | [Next in Thread] |