[Users] fw: Migrating ovirt-engine to new server

[Itamar Heim]

On 10/03/2012 04:37 PM, Neil wrote:
> On Wed, Oct 3, 2012 at 4:20 PM, Itamar Heim <iheim at redhat.com> wrote:
>> On 10/03/2012 04:17 PM, Neil wrote:
>>>
>>> On Wed, Oct 3, 2012 at 4:06 PM, Itamar Heim <iheim at redhat.com> wrote:
>>>>
>>>> On 10/03/2012 04:04 PM, Neil wrote:
>>>>>
>>>>>
>>>>> Thanks for coming back to me.
>>>>>
>>>>> On Wed, Oct 3, 2012 at 4:00 PM, Itamar Heim <iheim at redhat.com> wrote:
>>>>>
>>>>>> do you need to keep the VMs, or just move the LUNs to create a new one?
>>>>>> if you just want to create a new one, you just need to clear the LUNs
>>>>>> (DD
>>>>>> over them) so engine will let you use them (or remove them from first
>>>>>> engine
>>>>>> which will format them for same end goal.
>>>>>
>>>>>
>>>>>
>>>>> I need to keep the VM's unfortunately.
>>>>> Logically speaking all I need to do is detach the main data domain
>>>>> from one ovirt-engine and re-attach it to the new ovirt-engine.
>>>>
>>>>
>>>> sadly, not that easy yet (though just discussed today the need to push
>>>> this
>>>> feature).
>>>>
>>>> easiest would be to export them to an nfs export domain, re-purpose the
>>>> LUNs, and import to the new system.
>>>>
>>>> if not feasible, need to hack a bit probably.
>>>
>>>
>>> Oh crumbs! I thought that was wishful thinking though :)
>>>
>>> Exporting the VM's to NFS will take too long due to the total size
>>> being 4TB and the VM's are a mail, proxy and pdc servers so getting
>>> that much downtime won't be possible. Is attempting the upgrade
>>> path(http://wiki.ovirt.org/wiki/OVirt_3.0_to_3.1_upgrade) again my
>>> only option then?
>>> Even if I manage to get the "upgrade" working will I still need to
>>> export/import the VM's via NFS or will the datacentre move across once
>>> it can be detached?
>>>
>>
>> if you upgrade it the DC should be preserved.
>> juan - i remember there was a specific issue around upgrade to check, but
>> don't remember if was handled or not?
>
> Okay that is good news at least, very glad to hear!
> I am upgrading from a very early 3.1 release to the latest 3.1 using
> the dreyou repo, but encountered an issue after importing my DB I
> re-ran engine-setup and it kept asking for the engine password when it
> got to the point of "upgrading schema".
>

oh, not sure - that depends on the various versions dreyou used.
so this is 3.1-->3.1 (dreyou), not 3.0-->3.1?

> An idea I've just thought of which might work, is if I allocate
> additional LUNS(as I have spare drives inside the SAN) and mount it
> locally on the new system, and then share this via NFS to the old
> system as an export domain, then export the machines, then re-purpose
> the old LUNS and add these as a new storage domain. Does this sound
> like it might work? Logically it means the data is just copying from
> one set of LUNS to the other but still remaining on the SAN.

this should work.
though you are still copying all the data via the host, regardless of 
being on same SAN.