thr3ads.net - libvirt users - Re: does the guest have a snapshot ? [Feb 2020]

If this information is useful, please help other people find it:
Share via:

Lentes, Bernd

2020-Feb-07 14:25 UTC

does the guest have a snapshot ?

Hi,

i'm cuurently a bit confused if a guest does have a valid snapshot or not.
This is the xml:
 ...
   <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source
file='/var/lib/libvirt/images/crispor_1604/crispor_1604.sn'/>
      <backingStore type='file' index='1'>
        <format type='raw'/>
        <source
file='/var/lib/libvirt/images/crispor_1604/crispor_1604.img'/>
        <backingStore/>
      </backingStore>
      <target dev='vda' bus='virtio'/>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x04' function='0x0'/>
    </disk>
 ...

both files are currently in access by the respective qemu process.
lsof:
qemu-kvm  19533       root   13u      REG              253,0  29761732608  
12091393 /var/lib/libvirt/images/crispor_1604/crispor_1604.sn
qemu-kvm  19533       root   14r      REG              253,0 111561775513  
44793857 /var/lib/libvirt/images/crispor_1604/crispor_1604.img

Here are both files:
pc60181:/var/lib/libvirt/images/crispor_1604 # ll
 ...
-rw------- 1 root root 111561775513 Oct 22 15:23 crispor_1604.img
-rw-r--r-- 1 root root  29761732608 Feb  7 15:13 crispor_1604.sn

crispor_1604.sn has a recent timestamp.

The snapshot is currently in use:
virsh # domblklist crispor_1604
Target     Source
------------------------------------------------
vda        /var/lib/libvirt/images/crispor_1604/crispor_1604.sn


But virsh does not show any snapshot:

virsh # snapshot-list crispor_1604
 Name                 Creation Time             State
------------------------------------------------------------


So i'm a bit confused. Does it have a valid snapshot or not. How can i find
out and how can i get rid of it ?

Thanks.


Bernd

-- 

Bernd Lentes 
Systemadministration 
Institute for Metabolism and Cell Death (MCD) 
Building 35.34 - Raum 208 
HelmholtzZentrum münchen 
bernd.lentes@helmholtz-muenchen.de 
phone: +49 89 3187 1241 
phone: +49 89 3187 3827 
fax: +49 89 3187 2294 
http://www.helmholtz-muenchen.de/mcd

Perfekt ist wer keine Fehler macht 
Also sind Tote perfekt
Helmholtz Zentrum MÃ¼nchen

Helmholtz Zentrum Muenchen
Deutsches Forschungszentrum fuer Gesundheit und Umwelt (GmbH)
Ingolstaedter Landstr. 1
85764 Neuherberg
www.helmholtz-muenchen.de
Aufsichtsratsvorsitzende: MinDir.in Prof. Dr. Veronika von Messling
Geschaeftsfuehrung: Prof. Dr. med. Dr. h.c. Matthias Tschoep, Kerstin Guenther
Registergericht: Amtsgericht Muenchen HRB 6466
USt-IdNr: DE 129521671

Peter Krempa

2020-Feb-07 14:43 UTC

head link

Re: does the guest have a snapshot ?

On Fri, Feb 07, 2020 at 15:25:22 +0100, Lentes, Bernd
wrote:> Hi,
> 
> i'm cuurently a bit confused if a guest does have a valid snapshot or
not.
> This is the xml:
>  ...
>    <disk type='file' device='disk'>
>       <driver name='qemu' type='qcow2'/>
>       <source
file='/var/lib/libvirt/images/crispor_1604/crispor_1604.sn'/>
>       <backingStore type='file' index='1'>
>         <format type='raw'/>
>         <source
file='/var/lib/libvirt/images/crispor_1604/crispor_1604.img'/>
>         <backingStore/>
>       </backingStore>
>       <target dev='vda' bus='virtio'/>
>       <alias name='virtio-disk0'/>
>       <address type='pci' domain='0x0000'
bus='0x00' slot='0x04' function='0x0'/>
>     </disk>
>  ...
> 
> both files are currently in access by the respective qemu process.
> lsof:
> qemu-kvm  19533       root   13u      REG              253,0  29761732608  
12091393 /var/lib/libvirt/images/crispor_1604/crispor_1604.sn
> qemu-kvm  19533       root   14r      REG              253,0 111561775513  
44793857 /var/lib/libvirt/images/crispor_1604/crispor_1604.img
> 
> Here are both files:
> pc60181:/var/lib/libvirt/images/crispor_1604 # ll
>  ...
> -rw------- 1 root root 111561775513 Oct 22 15:23 crispor_1604.img
> -rw-r--r-- 1 root root  29761732608 Feb  7 15:13 crispor_1604.sn
> 
> crispor_1604.sn has a recent timestamp.
> 
> The snapshot is currently in use:
> virsh # domblklist crispor_1604
> Target     Source
> ------------------------------------------------
> vda        /var/lib/libvirt/images/crispor_1604/crispor_1604.sn
> 
> 
> But virsh does not show any snapshot:
> 
> virsh # snapshot-list crispor_1604
>  Name                 Creation Time             State
> ------------------------------------------------------------
> 
Libvirt is probably lacking the metadata for the snapshot. That is not a
problem though, because since libvirt doesn't support deletion of
external snapshots anyways currently you'd need to use the below
approach anyways.
> So i'm a bit confused. Does it have a valid snapshot or not. How can i
find out and how can i get rid of it ?
virsh blockcommit crispor_1604 vda --active --pivot

in the case above. that merges the
file='/var/lib/libvirt/images/crispor_1604/crispor_1604.sn'/
into file='/var/lib/libvirt/images/crispor_1604/crispor_1604.img'/ and
finishes the job.

If you have more complex backing chain you might want to use the --top
and --base arguments to control which portion to merge as the command
I've suggested merges everything into the bottom-most image.

Lentes, Bernd

2020-Feb-07 17:29 UTC

head link

Re: does the guest have a snapshot ?

----- On Feb 7, 2020, at 3:43 PM, Peter Krempa pkrempa@redhat.com wrote:
> On Fri, Feb 07, 2020 at 15:25:22 +0100, Lentes, Bernd wrote:
 ...> 
> Libvirt is probably lacking the metadata for the snapshot. That is not a
> problem though, because since libvirt doesn't support deletion of
> external snapshots anyways currently you'd need to use the below
> approach anyways.
> 
> virsh blockcommit crispor_1604 vda --active --pivot
> 
> in the case above. that merges the
> file='/var/lib/libvirt/images/crispor_1604/crispor_1604.sn'/
> into file='/var/lib/libvirt/images/crispor_1604/crispor_1604.img'/
and
> finishes the job.
> 
> If you have more complex backing chain you might want to use the --top
> and --base arguments to control which portion to merge as the command
> I've suggested merges everything into the bottom-most image.
Hi Peter,

i'm not lucky:

virsh help blockcommit does not know --active or --pivot.

virsh # help blockcommit

  SYNOPSIS
    blockcommit <domain> <path> [<bandwidth>] [<base>]
[--shallow] [<top>] [--delete] [--wait] [--verbose] [--timeout
<number>] [--async]

  OPTIONS
    [--domain] <string>  domain name, id or uuid
    [--path] <string>  fully-qualified path of disk
    [--bandwidth] <string>  bandwidth limit in MiB/s
    [--base] <string>  path of base file to commit into (default bottom of
chain)
    --shallow        use backing file of top as base
    [--top] <string>  path of top file to commit from (default top of
chain)
    --delete         delete files that were successfully committed
    --wait           wait for job to complete
    --verbose        with --wait, display the progress
    --timeout <number>  with --wait, abort if copy exceeds timeout (in
seconds)
    --async          with --wait, don't wait for cancel to finish
It does not say anything about the device.

I tried:

virsh # blockcommit crispor_1604 /var/lib/libvirt/images/crispor_1604.sn vda
--wait --verbose
error: bandwidth must be a number

virsh # blockcommit crispor_1604 /var/lib/libvirt/images/crispor_1604.sn --wait
--verbose
error: invalid argument: No device found for specified path

virsh # blockcommit crispor_1604 crispor_1604.sn --wait --verbose
error: invalid argument: No device found for specified path

virsh # blockcommit crispor_1604 vda --wait --verbose
error: Operation not supported: committing the active layer not supported yet

virsh # blockcommit crispor_1604 crispor_1604.sn --wait --verbose
error: invalid argument: No device found for specified path

virsh # blockcommit crispor_1604 crispor_1604.sn --verbose
error: missing --wait option

virsh # blockcommit crispor_1604 crispor_1604.sn
error: invalid argument: No device found for specified path

virsh # blockcommit crispor_1604 crispor_1604.sn vda
error: bandwidth must be a number

Am i missing something ? Is there an error or is my libvirt version to old ?
If yes, would it be successfull to copy the files to a host with more recent
libvirt, define it and then blockcommit ?

I have libvirt 1.2.5-15.3 (host is SLES 11 SP4).

Bernd
Helmholtz Zentrum München

Helmholtz Zentrum Muenchen
Deutsches Forschungszentrum fuer Gesundheit und Umwelt (GmbH)
Ingolstaedter Landstr. 1
85764 Neuherberg
www.helmholtz-muenchen.de
Aufsichtsratsvorsitzende: MinDir.in Prof. Dr. Veronika von Messling
Geschaeftsfuehrung: Prof. Dr. med. Dr. h.c. Matthias Tschoep, Kerstin Guenther
Registergericht: Amtsgericht Muenchen HRB 6466
USt-IdNr: DE 129521671

Reasonably Related Threads

Search for more maybe matching threads

libvirt users - Feb 2020 - Re: does the guest have a snapshot ?

does the guest have a snapshot ?

Re: does the guest have a snapshot ?

Re: does the guest have a snapshot ?

Reasonably Related Threads