[ovirt-users] Upgrade patch 3.5 -> 3.6

[Alexander Wels]

On Monday, February 15, 2016 02:40:47 PM Johan Kooijman wrote:
> Hi,
> 
> Can anybody recommend me best practice upgrade path for an upgrade from
> oVirt 3.5 on C6 to 3.6 on C7.2?

The answer sort of depends on what you want. Do you want no downtime on your 
VMs or is downtime acceptable. Also are you running hosted engine or not?

This is the basic plan which can be adjusted based on what your needs are:

1. Update engine from 3.5 to 3.6 (if hosted engine might be trickier, not sure 
haven't played with hosted engine).
2. Create a new 3.6 cluster.
3. Put 1 host in maintenance (which will migrate the VMs to the other hosts).
4. Remove the host from the DC.
5. Install C7.2 on the host
6. Add that host to the new 3.6 cluster.
7. Optional (you can cross cluster live migrate some VMs from 6 to 7 (just not 
the other way around, so once the VM is moved its stuck in the new cluster).
8. Go to 3 until all hosts are moved.
9. Your 3.5 cluster should now be empty, and can be removed.
10. Upgrade your DC to 3.6 (Can't upgrade if any lower clusters exist).

If you can have downtime, then just shut down the VMs running on the host in 
step 3 before putting it in maintenance. Once the host is moved to the new 
cluster you can start the VMs.

Alexander