[ovirt-users] How to migrate Self Hosted Engine

[Yedidyah Bar David]

On Mon, Nov 21, 2016 at 1:09 AM, Gianluca Cecchi
<gianluca.cecchi at gmail.com> wrote:
> On Sun, Nov 20, 2016 at 4:08 PM, Yedidyah Bar David <didi at redhat.com> wrote:
>>
>>
>>
>> There is now an option for this in the gui, did you mark it? See also:
>>
>> https://bugzilla.redhat.com/show_bug.cgi?id=1167262
>> --
>> Didi
>
>
> Ah.. I see.
> In "New Host" window there is a section named "Hosted Engine" and it
> defaults to "None" and I was give that..:
>
> https://drive.google.com/file/d/0BwoPbcrMv8mvME9CVGFRLTB0b0k/view?usp=sharing
>
> I didn't know it.
> I have verified I was able to put one host into maintenance (the only one
> running VM was automatically migrated) and then select "Reinstall" and in
> the proposed window I select now "Deploy" in similar hosted engine section:
> https://drive.google.com/file/d/0BwoPbcrMv8mvWTJMQXpwbHJYc00/view?usp=sharing
>
> It seems ok now

Mostly, yes.

> [root at ovirt02 ~]# hosted-engine --vm-status
>
>
> --== Host 1 status ==--
>
> Status up-to-date                  : True
> Hostname                           : ovirt01.localdomain.local
> Host ID                            : 1
> Engine status                      : {"health": "good", "vm": "up",
> "detail": "up"}
> Score                              : 3400
> stopped                            : False
> Local maintenance                  : False
> crc32                              : 8e1ee066
> Host timestamp                     : 429820
> Extra metadata (valid at timestamp):
> metadata_parse_version=1
> metadata_feature_version=1
> timestamp=429820 (Sun Nov 20 23:58:31 2016)
> host-id=1
> score=3400
> maintenance=False
> state=EngineUp
> stopped=False
>
>
> --== Host 2 status ==--
>
> Status up-to-date                  : True
> Hostname                           : 192.168.150.103

This is the address you provided in the ui, right?
I suggest to use a fqdn and make it well-resolvable. It will then be
easier to change the IP address if needed.

> Host ID                            : 2
> Engine status                      : {"reason": "vm not running on this
> host", "health": "bad", "vm": "down", "detail": "unknown"}
> Score                              : 3400
> stopped                            : False
> Local maintenance                  : False
> crc32                              : 839f79f5
> Host timestamp                     : 429736
> Extra metadata (valid at timestamp):
> metadata_parse_version=1
> metadata_feature_version=1
> timestamp=429736 (Sun Nov 20 23:58:37 2016)
> host-id=2
> score=3400
> maintenance=False
> state=EngineDown
> stopped=False
> [root at ovirt02 ~]#
>
> Is it?
> I was also able now to migrate the hosted engine vm to the second host and
> to connect without problems to its console.
> I'm going to change also the third host.
>
> Two notes:
> 1) it would be nice to pre-filter the drop down box when you have to choose
> the host where migrate the hosted engine...
> So that if there are no hosts available you will be given a related message
> without choice at all and if there is a subset of eligible hosts inside the
> cluster, you will be proposed only to choose one of them and not all the
> hosts inside the cluster.

Makes sense, please open an RFE to track this. Thanks.

>
> 2) If the gui option becomes the default and preferred way to deploy hosts
> in self hosted engine environments I think it should be put in clearer shape
> that if you follow the default action you would not have high availability
> for the hosted engine vm.
> Or changing the default action to "Deploy", or showing a popup if the hosted
> engine vm has only one host configured for it but there are other hosts in
> the cluster.
> Just my opinion.

Makes sense too, but I wonder if people will then be annoyed by forgetting
to uncheck it even after having enough HA hosts, which does have its cost
(both actual resource use and also reservations, IIUC). Perhaps we should
enable by default and/or remind only until you have enough HA hosts, which
can be a configurable number (and default e.g. to 3).

Best regards,
-- 
Didi