On Thu, Jun 30, 2016 at 9:34 AM, Paul Groeneweg | Pazion <paul@pazion.nl> wrote:
Hi Yedidyah,
Thank you for the comprehensive answers.
I think I go for a complete reinstall ( read also OS upgrade tool is not adviced on 6.6 or higher as there might be newer packages as on 7 ). No doubting to re-use current VM or setup from scratch ( fresh host with new hosted-engine and existing storage domein ).
You explain the steps ( 1 to 6 ), but then don't talk about storage domain import. Does it mean, when I reinstall the hosted-engine in the current he VM and restore an engine-backup ( step 5 ) I am able to start vm from Host and it is still connected to the master storage ( so no need for storage import) ?
Indeed - if you didn't touch the storage, the restored engine should already knows all it needs to know. Best,
Best Regards, Paul Groeneweg
Op do 30 jun. 2016 om 08:00 schreef Yedidyah Bar David <didi@redhat.com>:
On Wed, Jun 29, 2016 at 10:07 PM, Paul Groeneweg | Pazion <paul@pazion.nl> wrote:
I am looking for a way to get my hosted-engine running on el7 so I can upgrade to oVirt 4.0. Currently my hosts already run el7, but my hosted-engine is still el6.
I read
https://www.ovirt.org/documentation/how-to/hosted-engine-host-OS-upgrade/ but this is only about the hosts.
I read https://www.ovirt.org/documentation/how-to/hosted-engine/, but it only mentions upgrade of the hosted-engine software, not the OS.
I understood I can do a fresh hosted-engine install, and then import my storage domain to the new hosted engine, but:
- Do I need to restore my hosted engine database? ( like described here:
http://www.ovirt.org/develop/developer-guide/engine/migrate-to-hosted-engine... )
You might not have to, if you only care about the imported VMs from your storage. This will not keep other configuration, such as users/roles/permissions etc.
- Can I directly install hosted-engine 4.0 and then import the storage domain? Or should I install same hosted-engine version?
AFAIK 4.0 engine can import 3.6 storage domains without problem.
- Do I first need another master storage domain or can I directly import my old master storage domain?
No idea. Even if you do, you can create a small empty one and later remove it.
- When importing the storage domain what is the risk it fails ( I have backups, but it would cost a day to restore all )
No idea, but IIRC we got many successful reports and at most few failures for this.
- How long would import take? few minutes or hours? ( I want to keep down time as low as possible ).
Again no idea. Perhaps do some test?
Another option would be upgrade the OS ( with redhat-upgrade-tool ) or is this a path for disaster?
Didn't work for us well, so we decided to not support it. If you decide to try, make sure you test carefully beforehand. From ovirt's POV: 1. You'll need to handle postgresql upgrade. 2. Right after OS upgrade, you'll still have (I think) el6 packages of the engine. It will hopefully be in a good-enough state for upgrade to 4.0, but we didn't test this. 3. Specifically, if upgrade fails, rollback will most likely not work, so you'll have to manually handle this - take a full vm backup and make sure you can restore it.
I hope someone can tell me how I can smoothly upgrade my hosted-engine up to el7 and run oVirt 4.
We are working on a tool/wizard to help with this process. It used to work, but at some point it was decided that one of the actions it does is risky and was blocked, thus the tool is broken currently.
You can invoke the tool by running: 'hosted-engine --upgrade-appliance'. As noted above, this is currently broken.
There are several open bugs about it, e.g.:
https://bugzilla.redhat.com/show_bug.cgi?id=1319457 https://bugzilla.redhat.com/show_bug.cgi?id=1343425 https://bugzilla.redhat.com/show_bug.cgi?id=1343593 (closed, this is what broke the tool)
Basically, you can manually do what the tool is supposed to do: 1. Make sure state is clean and stable (no running/pending storage actions, no VMs in the middle of migration etc), all clusters are compat level 3.6, etc. 2. Move to global maintenance 3. backup the engine using engine-backup and keep the backup elsewhere 4. Reinstall engine vm with el7 and 4.0 engine (the tool will use the engine appliance, you might too but not sure how exactly). 5. Restore the backup and run engine-setup. 6. If all looks ok, leave global maintenance.
If you manually keep a full backup of the engine vm before step 4, you might be able to restore this backup if there are problems. Doing this in the provided tool is currently the main blocking issue for it. Hopefully will be provided in 4.0.1.
Best, -- Didi
-- Didi