[ovirt-users] Can't remove snapshot due to low disk space on storage domain?

Wed Feb 11 12:44:55 UTC 2015

Hi,

I created the snapshot on the Snapshots subtab of the Virtual machines 
tab. I did this when my engine (and host) was running oVirt 3.4. It 
is/was a snapshot of the entire VM (I deselected the memory state).

I since upgraded the engine to 3.5.

When I look at the snapshots subtab of the virtual machine, I see the 
Current snapshot which is "Active VM" and the snapshot I created before. 
This snapshot is a snapshot of both the OS and data disk.

I can not delete the second snapshot when the VM is running. If I power 
down the VM, I can't remove the snapshot as it brings up the error I 
mentioned before.

However, when I look at the disk snapshots subtab of the storage tab 
(like you suggested), I see both disks with a snapshot and I can select 
"Remove" there while the VM is running. Is it safe to remove them this 
way? This will only remove the snapshot and not the disk (and data) from 
my (running) VM?

Regards,

Rik

On 02/11/2015 01:26 PM, Elad Ben Aharon wrote:
> I'm not sure I understand which RHEV version you're using now.
> If you're using RHEV 3.5, it is possible to remove a snapshot of a
> single disk.
> You can do it via webadmin, Under the 'Disks Snapshots' subtab of the
> relevant storage domain, in the 'Storage' main tab.
>
> As for your second question, the free space has to be in the same
> storage domain.
> ------------------------------------------------------------------------
> *From: *"Rik Theys" <Rik.Theys at esat.kuleuven.be>
> *To: *"Elad Ben Aharon" <ebenahar at redhat.com>
> *Cc: *users at ovirt.org
> *Sent: *Wednesday, 11 February, 2015 2:10:13 PM
> *Subject: *Re: [ovirt-users] Can't remove snapshot due to low disk
> space        on storage domain?
>
> Hi,
>
> Thats unfortunate :-(. It would have been great if oVirt told me during
> the creation of the snapshot that I would be unable to remove it later
> due to unsufficient free space in the storage domain :-).
>
> The VM has two disks - a small and a large one - so the snapshot
> contains both. Can I still remove the large disk while it has snapshots?
>
> Luckily the used disk space in the (preallocated) large disk is low
> enough so I can fit it on another temporary disk then.
>
> Does the free space have to be in the same storage domain, or can oVirt
> use another storage domain for the temporary volume? IOW, can I add an
> NFS storage domain which oVirt can use to create the temporary disk on?
>
> Regards,
>
> Rik
>
>
> On 02/11/2015 12:57 PM, Elad Ben Aharon wrote:
>  > *equals or larger than the disk size
>  >
>  > ------------------------------------------------------------------------
>  > *From: *"Elad Ben Aharon" <ebenahar at redhat.com>
>  > *To: *"Rik Theys" <Rik.Theys at esat.kuleuven.be>
>  > *Cc: *users at ovirt.org
>  > *Sent: *Wednesday, 11 February, 2015 12:18:35 PM
>  > *Subject: *Re: [ovirt-users] Can't remove snapshot due to low disk
>  > space        on        storage domain?
>  >
>  > Snapshot removal (merge) includes a create volume phase. This volume is
>  > temporary and gets removed once the snapshot merge is completed. Its
>  > size is the size of the disk.
>  > That means that in order to remove the snapshot, the storage domain
>  > should have available size that is equal to the disk size.
>  >
>  >
>  >
>  >
>  >
>  >
>  >
>  >
>  >
>  > Elad Ben Aharon
>  > RHEV-QE storage
>  >
>  >
>  > ------------------------------------------------------------------------
>  > *From: *"Rik Theys" <Rik.Theys at esat.kuleuven.be>
>  > *To: *users at ovirt.org
>  > *Sent: *Tuesday, 10 February, 2015 12:00:10 PM
>  > *Subject: *[ovirt-users] Can't remove snapshot due to low disk space
>  > on        storage domain?
>  >
>  > Hi,
>  >
>  > I'm running the ovirt engine 3.4 series. I've created a snapshot of a VM
>  > with an OS and data disk before upgrading the machine.
>  >
>  > The upgrade went fine and I now want to remove the snapshot.
>  > Unfortunately this fails with the error:
>  >
>  > "Cannot remove Snapshot. Low disk space on target Storage Domain
>  > stadius-virt2_PERC."
>  >
>  > So I can't free disk space by removing the snapshot because I don't have
>  > enough space?
>  >
>  > When I look at the VM the disks are shown as preallocated (which is what
>  > I selected during installation). When I look at the storage tab and list
>  > the disks in my storage domain, the disks are now shown as thin
>  > provisioned with the actual size > virtual size.
>  >
>  > How can I remove this snapshot? I don't have enough free disk space in
>  > my storage domain to duplicate the data disk of my VM.
>  >
>  > Regards,
>  >
>  > Rik
>  >
>  >
>  > --
>  > Rik Theys
>  > System Engineer
>  > KU Leuven - Dept. Elektrotechniek (ESAT)
>  > Kasteelpark Arenberg 10 bus 2440  - B-3001 Leuven-Heverlee
>  > +32(0)16/32.11.07
>  > ----------------------------------------------------------------
>  > <<Any errors in spelling, tact or fact are transmission errors>>
>  > _______________________________________________
>  > Users mailing list
>  > Users at ovirt.org
>  > http://lists.ovirt.org/mailman/listinfo/users
>  >
>  >
>  > _______________________________________________
>  > Users mailing list
>  > Users at ovirt.org
>  > http://lists.ovirt.org/mailman/listinfo/users
>  >
>
>
> --
> Rik Theys
> System Engineer
> KU Leuven - Dept. Elektrotechniek (ESAT)
> Kasteelpark Arenberg 10 bus 2440  - B-3001 Leuven-Heverlee
> +32(0)16/32.11.07
> ----------------------------------------------------------------
> <<Any errors in spelling, tact or fact are transmission errors>>
>

-- 
Rik Theys
System Engineer
KU Leuven - Dept. Elektrotechniek (ESAT)
Kasteelpark Arenberg 10 bus 2440  - B-3001 Leuven-Heverlee
+32(0)16/32.11.07
----------------------------------------------------------------
<<Any errors in spelling, tact or fact are transmission errors>>