[libvirt-users] snapshot of a raw file - how to revert ?

[Lentes, Bernd]

----- On Feb 13, 2018, at 1:38 PM, Bernd Lentes bernd.lentes at helmholtz-muenchen.de wrote:

> Hi,
> 
> i have the following system:
> 
> pc59093:~ # cat /etc/os-release
> NAME="SLES"
> VERSION="11.4"
> VERSION_ID="11.4"
> PRETTY_NAME="SUSE Linux Enterprise Server 11 SP4"
> ID="sles"
> ANSI_COLOR="0;32"
> CPE_NAME="cpe:/o:suse:sles:11:4"
> 
> pc59093:~ # uname -a
> Linux pc59093 3.0.101-84-default #1 SMP Tue Oct 18 10:32:51 UTC 2016 (15251d6)
> x86_64 x86_64 x86_64 GNU/Linux
> 
> pc59093:~ # rpm -qa|grep -iE 'libvirt|kvm'
> libvirt-cim-0.5.12-0.7.16
> libvirt-python-1.2.5-1.102
> libvirt-client-1.2.5-15.3
> kvm-1.4.2-47.1
> sles-kvm_en-pdf-11.4-0.33.1
> libvirt-1.2.5-15.3
> 
> 
> I have several guests running with raw files, which is sufficent for me. Now i'd
> like to snapshot one guest because i make heavy configuration changes on it.
>>From what i read in the net is that libvirt supports snapshoting of raw files
>>when the guest is shutdown and the file of the snapshot becomes a qcow2. Right
>>?
> I try to avoid converting my raw file to a qcow2 file. I can shutdown the guest
> for a certain time, that's no problem. I don't need a live snapshot.
> But how can i revert to my previous state if my configuration changes go wrong ?
> Can i do this with snapshot-revert or do i have to edit the xml file and point
> the hd again to the origin raw file ?
> What i found in the net wasn't complete clear.
> 
> Thanks.
> 

Hi,

i found that: https://dustymabe.com/2015/01/11/qemu-img-backing-files-a-poor-mans-snapshotrollback/

I tried it and it seemed to work, although my root fs was checked after the commit, anything else seemed to work.
What do you think of this procedure ?

Bernd
 

Helmholtz Zentrum München