From: Eric Blake <eblake@redhat.com>
To: Max Reitz <mreitz@redhat.com>, lihuiba <magazine.lihuiba@163.com>
Cc: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] qcow2 snapshot + resize
Date: Wed, 6 Jan 2016 09:28:28 -0700 [thread overview]
Message-ID: <568D40AC.5050901@redhat.com> (raw)
In-Reply-To: <568D3EDD.1090205@redhat.com>
[-- Attachment #1: Type: text/plain, Size: 903 bytes --]
On 01/06/2016 09:20 AM, Max Reitz wrote:
>> If I take a snapshot while the guest sees a 1G disk, then resize the
>> disk to 2G, then roll back to the point in time of the snapshot, I'd
>> expect the disk to roll back to 1G in size. Anything else is likely to
>> confuse the guest. And that's what current resize support already does
>> (it only resizes the active image, not the snapshots).
>
> No, the current resize operation just refuses to resize the image if it
> has any snapshots. Snapshots currently do not store the size of the
> image when they were created.
Huh? I thought that we specifically added bytes 48-55 per snapshot entry
in the qcow2v3 description specifically so that internal snapshots DO
record the size of the image when the snapshot was created.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 604 bytes --]
next prev parent reply other threads:[~2016-01-06 16:28 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-05 12:10 [Qemu-devel] qcow2 snapshot + resize lihuiba
2016-01-05 13:55 ` Eric Blake
2016-01-05 17:36 ` John Snow
2016-01-06 2:50 ` lihuiba
2016-01-06 15:04 ` Eric Blake
2016-01-06 16:20 ` Max Reitz
2016-01-06 16:28 ` Eric Blake [this message]
2016-01-06 16:30 ` Max Reitz
2016-01-14 12:17 ` Kevin Wolf
2016-01-19 2:42 ` lihuiba
-- strict thread matches above, loose matches on Subject: below --
2015-12-29 9:38 lihuiba
2016-01-04 17:38 ` Max Reitz
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=568D40AC.5050901@redhat.com \
--to=eblake@redhat.com \
--cc=magazine.lihuiba@163.com \
--cc=mreitz@redhat.com \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.