[ovirt-users] upgrade hosted-engine os ( not hosts )

Paul Groeneweg | Pazion paul at pazion.nl
Thu Jun 30 18:46:57 UTC 2016


Things are getting more clear to me, thanks!
And this whole upgrade is something I should prepare well and not try to do
in a few hours at night :)

Resuming, there are multiple solutions:

1. upgrade el6 to el7
no go => I need to upgrade postgresql and redhat warns about upgrading 6.6
to 7 because of newer packages
2. install a new HE on new Host new storage domain
a lot of work  => I have to turn off VMs, import storage domain into new
setup and reinstall hosts.
3. install a new HE on new Host existing storage domain
possibly not without issues => I have to manually update references to the
hosted storage or better wait till there is an upgrade tool.
4. (re)install HE in current VMS container.
=> I can keep my Hosts and reference to the storage domain.

So I guess my best bet is to go for option 4.

The flow I am planning to follow would be:

1. Move to global maintenance ( keep VMs running )
2. backup ( I have also a complete disk install of old hosted-engine )
3. reboot with different conf, to boot from cd
4. acces console and run install + import the backup in the engine vm
? 5. run engine-setup to configure new install with engine restore data
6. reboot hosted-engine
7. Remove from global maintenance
8. launch web gui and I should be able to manage all still running VMs
again.

Would above be working or am I missing something and I  doubt step 5. Is
this needed?

Best Regards,
Paul



Op do 30 jun. 2016 om 14:44 schreef Simone Tiraboschi <stirabos at redhat.com>:

> On Thu, Jun 30, 2016 at 8:34 AM, Paul Groeneweg | Pazion <paul at 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 ).
>
> If you are planning to redeploy hosted-engien from scratch and
> restoring on the new engine DB a backup of the previous one, please
> carefully consider this:
> https://bugzilla.redhat.com/show_bug.cgi?id=1240466#c21
>
> So, if you choose that path you'll have also to manually remove any
> reference to the previous hosted-engine from the restored DB.
> I'd strongly suggest you to wait for the upgrade tool to be fixed
> since manually doing this upgrade can be really error prone.
>
> > 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) ?
> >
> > Best Regards,
> > Paul Groeneweg
> >
> >
> > Op do 30 jun. 2016 om 08:00 schreef Yedidyah Bar David <didi at redhat.com
> >:
> >>
> >> On Wed, Jun 29, 2016 at 10:07 PM, Paul Groeneweg | Pazion
> >> <paul at 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
> >
> >
> > _______________________________________________
> > Users mailing list
> > Users at ovirt.org
> > http://lists.ovirt.org/mailman/listinfo/users
> >
>
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