[ovirt-users] global vs local maintenance with single host

[Yedidyah Bar David]

On Sat, Sep 3, 2016 at 1:18 PM, Gianluca Cecchi
<gianluca.cecchi at gmail.com> wrote:
> Hello,
> how do the two modes apply in case of single host?
> During an upgrade phase, after having upgraded the self hosted engine and
> leaving global maintenance and having checked all is ok, what is the correct
> mode then to put host if I want finally to update it too?

The docs say to put hosts to maintenance from the engine before upgrading them.

This is (also) so that VMs on them are migrated away to other hosts.

With a single host, you have no other hosts to migrate VMs to.

So you should do something like this:

1. Set global maintenance (because you are going to take down the
engine and its vm)
2. Shutdown all other VMs
3. Shutdown engine vm from itself
At this point, you should be able to simply stop HA services. But it
might be cleaner to first set local maintenance. Not sure but perhaps
this might be required for vdsm. So:
4. Set local maintenance
5. Stop HA services. If setting local maintenance didn't work, perhaps
better stop also vdsm services. This stop should obviously happen
automatically by yum/rpm, but perhaps better do this manually to see
that it worked.
6. yum (or dnf) update stuff.
7. Start HA services
8. Check status. I think you'll see that both local and global maint
are still set.
9. Set maintenance to none
10. Check status again - I think that after some time HA will decide
to start engine vm and should succeed.
11. Start all other VMs.

Didn't try this myself.

Best,
-- 
Didi