[ovirt-users] IO errors when adding new disk on iSCSI storage

Dafna Ron dron at redhat.com
Fri May 16 13:04:00 UTC 2014

adding federico since I think he can probably add more info here.

when we use thin provisionining we have to extend the disk during 
writing (it's set to do that every 2GB I think).
during extend the vm pauses and resumes.

However, this action should not be noticeable by the vm user.

Does the vm pause and resumes or pauses completely? is it noticeable by 
the vm user?


On 05/16/2014 01:40 PM, John Taylor wrote:
> Hi Morten,
> My understanding of thin disks on a block domain is that vdsm traps
> ENOSPC on the thin lv and uses the mailbox to get the SPM to extend
> it.   See a presentation by Nir
> http://www.ovirt.org/File:Storage-mailbox.odp
> I thought I saw somewhere there were some changes/bugs around that for
> allowing mixed data centers (both block and file domains). ...just
> looked now and this bz looks relevant
> https://bugzilla.redhat.com/show_bug.cgi?id=1083476
> So maybe you could check the engine logs and spm logs for that flow
> (sorry I can't tell you any specifics about what you should look for )
> -John
> On Fri, May 16, 2014 at 1:54 AM, Morten A. Middelthon <morten at flipp.net> wrote:
>> Hi,
>> I just re-ran the test with adding a preallocated disk, and the problem did
>> _not_ appear. I tried a few times to write large files with dd, but the vm
>> continued to run without problems
>> with regards,
>> --
>> Morten A. Middelthon
>> Email: morten at flipp.net
>> Phone: +47 907 83 708
>> _______________________________________________
>> Users mailing list
>> Users at ovirt.org
>> http://lists.ovirt.org/mailman/listinfo/users

Dafna Ron

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