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

[Gianluca Cecchi]

Il 28/Set/2016 21:09, "Gervais de Montbrun" <gervais at demontbrun.com> ha
scritto:
>
> Hi Gianluca,
>
> Instead of editing the system's built in systemd configuration, you can
do the following...
>
> Create a file called /etc/systemd/system/ovirt-ha-broker.service
>
>> # My custom ovirt-ha-broker.service config that ensures NFS starts
before ovirt-ha-broker.service
>> # thanks Gervais for this tip!  :-)
>>
>> .include /usr/lib/systemd/system/ovirt-ha-broker.service
>>
>> [Unit]
>> After=nfs-server.service
>
>
> Then disable and enable ovirt-ha-broker.service (systemctl disable
ovirt-ha-broker.service ; systemctl enable ovirt-ha-broker.service) and you
should see that it is using your customized systemd unit definition. You
can see that systemd is using your file by running systemctl status
ovirt-ha-broker.service. You'll see something like "Loaded: loaded
(/etc/systemd/system/ovirt-ha-broker.service;" in the output.
>
> Your file will survive updates and therefore always wait for nfs to start
prior to starting. You can do the same for your other customizations.
>
> Cheers,
> Gervais
>
>
>
>> On Sep 28, 2016, at 1:31 PM, Gianluca Cecchi <gianluca.cecchi at gmail.com>
wrote:
>>
>> On Sun, Sep 4, 2016 at 10:54 AM, Yedidyah Bar David <didi at redhat.com>
wrote:
>>>
>>> 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
>>
>>
>> Hello Didi,
>> I would like to leverage the update I have to do on 2 small different
lab environments to crosscheck the steps suggested.
>> They are both single host environments with self hosted engine.
>> One is 4.0.2 and the other is 4.0.3. Both on CentoS 7.2
>> I plan to migrate to the just released 4.0.4
>>
>> One note: in both environments the storage is NFS and is provided by the
host itself, so a corner case (for all hosted_storage domain, main data
domain and iso storage domain).
>> I customized the init scripts, basically for start phase of the server
and to keep in count of the NFS service, but probably something has to be
done for stop too?
>>
>> 1) In /usr/lib/systemd/system/ovirt-ha-broker.service
>>
>> added in section [Unit]
>>
>> After=nfs-server.service
>>
>> The file is overwritten at update so one has to keep in mind this
>>
>> 2) also in vdsmd.service changed
>> from:
>> After=multipathd.service libvirtd.service iscsid.service rpcbind.service
\
>>       supervdsmd.service sanlock.service vdsm-network.service
>>
>> to:
>> After=multipathd.service libvirtd.service iscsid.service rpcbind.service
\
>>       supervdsmd.service sanlock.service vdsm-network.service \
>>       nfs-server.service
>>
>> Do you think any order setup I have to put in place related to NFS
service and oVirt services stop?
>>
>> _______________________________________________
>> Users mailing list
>> Users at ovirt.org
>> http://lists.ovirt.org/mailman/listinfo/users
>
>

Nice! I'm going to try and see.
Any particular dependency I should add for shutdown order due to the fact
that my host is also the NFS server providing data stores?
Do I need to set up nfs stop only after a particular ovirt related service?
Thanks,
Gianluca
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