[Users] scheduling storage migration

[Itamar Heim]

On 04/06/2014 07:12 PM, Gilad Chaplik wrote:
> ----- Original Message -----
>> From: "Itamar Heim" <iheim at redhat.com>
>> To: "Gilad Chaplik" <gchaplik at redhat.com>
>> Cc: "Jorick Astrego" <j.astrego at netbulae.eu>, "users" <users at ovirt.org>
>> Sent: Sunday, April 6, 2014 7:06:51 PM
>> Subject: Re: [Users] scheduling storage migration
>>
>> On 04/06/2014 06:16 PM, Gilad Chaplik wrote:
>>> ----- Original Message -----
>>>> From: "Itamar Heim" <iheim at redhat.com>
>>>> To: "Jorick Astrego" <j.astrego at netbulae.eu>
>>>> Cc: "users" <users at ovirt.org>
>>>> Sent: Friday, April 4, 2014 3:52:01 PM
>>>> Subject: Re: [Users] scheduling storage migration
>>>>
>>>> On 04/04/2014 03:34 PM, Jorick Astrego wrote:
>>>>>
>>>>> On Fri, 2014-04-04 at 15:02 +0300, Itamar Heim wrote:
>>>>>> On 04/04/2014 10:51 AM, Jorick Astrego wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> I don't know if it's possible yet but can we schedule the (live)
>>>>>>> storage
>>>>>>> migration?
>>>>>>>
>>>>>>> It would be awesome to have for example some VM data on SSD storage
>>>>>>> that
>>>>>>> migrates to HDD storage when the VM is shutdown. Or have VM's with high
>>>>>>> IO load during specific times migrate to a high IO storage domain
>>>>>>> during
>>>>>>> these hours.
>>>>>>
>>>>>> if the VM is down, you can move it, not (live) storage migration.
>>>>>>>
>>>>>>> I realize it will generate extra load while migrating but this can be
>>>>>>> planned for. Maybe the guys from glusterfs could enable storage
>>>>>>> migration on their side so the migration can execute on the storage
>>>>>>> server triggered by ovirt, that would be even better performance wise.
>>>>>>
>>>>>> in any case, you can script anything with the API...
>>>>>>
>>>>>
>>>>> I was being lazy... So I can use the
>>>>> http://www.ovirt.org/Features/oVirtSchedulerAPI for this? Or do I have
>>>>> to hack around with the engine api. I will spend some time diving into
>>>>> it.
>>>>
>>>> you can use the scheduler api, but I don't remember it having an event
>>>> for OnVmStop.
>>>> you can also use it for a periodic "balancing" call, but for that, you
>>>> can also just use cron.
>>>> in either case you will need to do the relevant api calls for moving the
>>>> disks around. i'd go with the cron approach.
>>>
>>> What about a vdsm hook?
>>
>> you can't move things around not via engine or you will lose the sync
>> between them
>>
>
> sure, meant using the python SDK within the hook (the trigger).

I think a cron on engine is a much simpler place.