[ovirt-users] volume_utilization_chunk_mb not working

[Nir Soffer]

On Fri, May 13, 2016 at 1:34 PM, Grundmann, Christian
<Christian.Grundmann at fabasoft.com> wrote:
> Hi
>
> I create a lot of Thin Disk VMs from templates every day, and get „paused
> due to no storage space error“ and „paused due to unknown storage error“ on
> a few of them.
>
> Sometimes the VMs are resumed a few seconds later but sometime not, but I
> can resume them myself.
>
>
>
> I tried to set
>
> volume_utilization_percent=15
>
> volume_utilization_chunk_mb=4048

This looks correct if this is in the [irs] section of the configuration.

[irs]

# Together with volume_utilization_chunk_mb, set the minimal free
# space before a thin provisioned block volume is extended. Use lower
# values to extend earlier.
# volume_utilization_percent = 50

# Size of extension chunk in megabytes, and together with
# volume_utilization_percent, set the free space limit. Use higher
# values to extend in bigger chunks.
# volume_utilization_chunk_mb = 1024


To get the correct configuration format, you can do:
python /usr/lib/python2.7/site-packages/vdsm/config.py

>
>
>
> in /etc/vdsm/vdsm.conf on every Host
>
>
>
> But the Initial Size of the Disk is always 1GB and then increments to 2GB

Please share the vdsm.conf file with these settings.

>
>
>
> 4GB would be the maximum Size I need before I destroy the VM. So if the
> initial Size would be 4GB the pausing shouldn’t happen anymore

The initial volume size is always 1GiB, regardless of these settings.

After creating 1GiB lv, we extend the lv volume_utilization_chunk_mb megabytes.

So your setting will result in 1GiB lv, and after you write about
150MiB, it will be extended
to 5GiB.

So I guess that you want to use
volume_utilization_chunk_mb = 3072

Which will give you 4GiB lv after the first extend.

We support initialSize argument when creating volumes - use when importing
external vms (v2v), but it is not exposed in the ui.

If you think think exposing it in the ui is a useful feature, you can
file a bug:
https://bugzilla.redhat.com/enter_bug.cgi?product=ovirt-engine

Nir