[please don't top-post on technical lists]
Okay, sorry about that.
>
> Thank you for your suggestions. Here is what happened when I tried
the
> snapshot. I will try the dd a bit later.
>
> VERSIONS
> virsh: 0.9.10
> qemu: 2.0.12
Huh? The current upstream version of qemu is 1.2; I don't
recognize
the
2.0.12 numbering.
Sorry about that. It was a typo. The version seems to be 0.12.1.2. from
running
$ /usr/libexec/qemu-kvm --version
QEMU PC emulator version 0.12.1 (qemu-kvm-0.12.1.2), Copyright (c)
2003-2008 Fabrice Bellard
>
> DOM: webdev
>
> $ ls -l /proc/13196/fd/9
> lrwx------. 1 qemu qemu 64 Nov 5 11:57 /proc/13196/fd/9 ->
> /tools/vm/images/webdev.img (deleted)
>
> $ cp /proc/13196/fd/9 /tools/vm/images/webdev.img
> cp: cannot stat `/proc/13196/fd/9': Stale NFS file handle
>
> $ virsh snapshot-create-as webdev \
> --no-metadata \
> --disk-only \
> --diskspec
> /tools/vm/images/webdev.img,file=/tools/vm/images/webdev.img1
> error: unsupported configuration: no disk named
> '/tools/vm/images/webdev.img'
What does this say?
virsh domblklist webdev
Target Source
------------------------------------------------
vda /var/lib/libvirt/images/webdev.img
hdc -
That is the name of the disk where you are creating the snapshot.
The --diskspec line needs two pieces of information: a designation
for the current file being snapshotted (either the absolute path
you used in your xml, or the shorthand name like 'vda' - valid
names are found by the domblklist command); and the name of the
new file to create the snapshot as.
The fact that your error message complains about "no disk named
'/tools/vm/images/webdev.img'" says that you probably didn't spell
the file the same as it was named in the XML; seeing the domblklist
command will make it clear what name you should be using instead.
I see. Thank you for the clear explanation. It appears that the file
name in the XML and the file name referenced by the fd are different:
/var/lib/libvirt/images/webdev.img (XML, link, domblklist)
/tools/vm/images/webdev.img (filer, fd reference)
I modified the command to use /var/lib/libvirt/images/webdev.img but it
had a different problem:
# virsh snapshot-create-as webdev \
--no-metadata \
--disk-only \
--diskspec
/var/lib/libvirt/images/webdev.img,file=/tools/vm/images/webdev.img1
error: operation failed: Failed to take snapshot: unknown command:
'snapshot_blkdev'
I don't understand what the message is trying to tell me. Why would
snapshot_blkdev not be available? Perhaps the version I have is too old?
>
> # Pull the contents into the new file
> virsh blockpull $dom /tmp/guest.img1 --wait --verbose
For the blockpull command, the same usage applies - you name the disk
by its path (but
note that you just changed the path as a result of the
snapshot-create-as command; as
another domblklist would prove) or by its > device name, such as
vda.
I see.
BTW, I tried the dd option with another guest and it seemed to work.
Thank you,
Joe
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library
http://libvirt.org