On Thu, Nov 19, 2020 at 4:37 PM Alex K <rightkicktech(a)gmail.com> wrote:
Hi all,
I have a corrupt self-hosted engine (with several file system errors,
postgres not able to start) and thus it does not give access to the web UI.
This happened following an unlucky split brain resolution (I am running 2
nodes). The two hosts are running VMs also which I would like to keep
running as they are needed.
When trying to boot into rescue mode (using systemd.unit=emergency.target
boot parameter) I get a cursor and nothing else.
This means that more than just the DB is corrupt...
I have backups of engine files with scope all (using the engine-backup
tool).
What is the best approach to try and fix the engine or redeploy.
If you are careful, and know what you are doing, you can try something like
the following. I am not giving many details, hopefully you can find on the
net tutorials about how to use the things I suggest:
1. Move to global maintenance
2. Stop the current dead vm (if needed)
3. Find current vm conf, edit it to boot from a rescue iso image of your
preference or from net/PXE etc., and start the vm with '--vm-conf' pointing
to your edited file.
4. Connect a console (hosted-engine --console, or 'virsh console', or use
'--add-console-password' and remote viewer, if needed)
5. Clean the disk and install the OS, oVirt, etc.
6. Copy your backup into the vm and restore with engine-backup
7. Then cleanly stop the machine, exit global maint, and let HA start it
(or start it yourself with --vm-start).
At the time, we had a bug [1] to document this. The result is [2]. It does
not detail how to boot/reinstall os/etc., only restore (if e.g. db is dead
but fs is ok).
For something somewhat similar to what you want, see also [3], which uses
guestfish. Might be useful, depending on how badly your disk is corrupted.
How did you run into a split brain? There is a lock on the shared storage
that should prevent this.
Good luck and best regards,
[1]
https://bugzilla.redhat.com/show_bug.cgi?id=1482710
[2]
https://www.ovirt.org/documentation/administration_guide/#Overwriting_a_S...
[3]
https://bugzilla.redhat.com/show_bug.cgi?id=1569827#c4
--
Didi