[Users] Command line : how to add a removed host?

[Nicolas Ecarnot]

Hi,

Doing some tests, I set 2 hosts into maintenance mode, then "removed" them.

When trying to add them back into the cluster, I found nothing more than 
the "new" action.
Using it and configuring the IP address, I see oVirt re-installing many 
packages.
Once installed, the host can not be added because :
"Host host016 is installed with VDSM version (4.13) and cannot join 
cluster cluster21 which is compatible with VDSM versions [4.9, 4.11, 
4.12, 4.10]."

In fact, I have 2 questions:

- For the second host (still untouched), is there a way to add it back 
into the cluster without re-installing the packages maybe via the 
command line) (and then preventing this version issue)?
- For the weeks to come, I see I'll have to upgrade some parts. I don't 
know what is needed to upgrade for the VDSM version to get upgraded 
("for [4.9, 4.11, 4.12, 4.10] to increase"). Obviously, I don't want to 
break the whole cluster while upgrading it.

Thank you.

-- 
Nicolas Ecarnot