[Qemu-devel] Issue with snapshot outside qcow2 disk - qemu 0.14.0

[SAURAV LAHIRI]

Hello,
I attempted to create snapshots outside the original qcow2 disk, a feature that is available with 0.14.0, but facing an unexpected behaviour as described below. Any help is greatly appreciated.

I am using qemu version 0.14

# qemu --version
QEMU emulator version 0.14.0, Copyright (c) 2003-2008 Fabrice Bellard


# qemu-img --version
qemu-img version 0.14.0, Copyright (c) 2004-2008 Fabrice Bellard
usage: qemu-img command [command options]
QEMU disk image utility


Following steps were executed to copy a snapshot outside the original qcow2 but looks like there is an issue.

1. VM(vm1) brought up with a qcow2 image(/home/user1/lucid-vm2). This is a lucid 10.04 VM.

2. Next snapshot created for the qcow2
   #qemu-img snapshot -c snap1 /home/user1/lucid-vm2

3. Lets see if the snapshot got created.
    # qemu-img snapshot -l /home/user1/lucid-vm2
    Snapshot list:
    ID        TAG                 VM SIZE                DATE       VM CLOCK
    1         snap1                     0 2011-03-09 23:17:53   00:00:00.000


4. Next inside the running VM(vm2) a new file is created. Since the snapshot was
    created before creating this file. The snapshot should not have this file.
   #touch samplefile

5. Now the snapshot snap1 is copied outside the original qcow2 image.
   qemu-img convert -f qcow2 -O qcow2 -s snap1 /home/user1/lucid-vm2 /home/user1/lucid-vm2-snap1

6. Next shutdown VM(vm1) and bring it up the snapshot image /home/user1/lucid-vm2-snap1.
   Since the snapshot was created before creating the file named "samplefile" it is to
   be expected that the file should not be there in the snapshot image. But the file does appear  in the snapshot image
   #ls samplefile
   samplefile
   

Regards
sl