[ClusterLabs] [EXT] Rebuild of failed node

[Fabrizio Ermini]

Hi Ulrich, and thanks for your reply. In this case, the missing node has
been wiped and formatted. Reason wasn't an actual fault, but rather the
need to change storage configuration (we had to comply with a security
requirement that involved adding cryptography at rest of cluster volumes).
I intended to use this activity also as a test bed to learn what was the
correct procedure to follow in case of a node loss, so that I could be
already sure on how to proceed in an emergency. These servers are not under
backup: they are meant to work as edge servers, collecting data and
shipping them up towards main production servers. We have a golden image
that allows us to reinstall them quickly, but the installation procedure is
based on the assumption that both nodes are installed together: at the
moment I haven't a procedure to reinstall just one of the nodes, and that's
what I'd like to create.

I hope that this can clarify your doubts,  best regards
Fabrizio


Il giorno lun 12 mag 2025 alle ore 08:41 Windl, Ulrich <u.windl at ukr.de> ha
scritto:

> Maybe explain what “failed node” and “rebuild” actually means:
>
> It was fenced, or was it reinstalled, or did you have a fatal disk failure?
>
> Usually a backup is your best friend.
>
>
>
> Kind regards,
>
> Ulrich Windl
>
>
>
> *From:* Users <users-bounces at clusterlabs.org> *On Behalf Of *Fabrizio
> Ermini
> *Sent:* Friday, May 9, 2025 4:26 PM
> *To:* users at clusterlabs.org
> *Subject:* [EXT] [ClusterLabs] Rebuild of failed node
>
>
>
> Hi all! Freshmen here, just joined.
>
>
>
> I'm currently in the need to rebuild a failed node on a
> pacemaker2.1/corosync3.1 2-node cluster with drbd storage.
>
> I've searched in Pacemaker docs and in the list archives, but I haven't
> found a clear guide on how to proceed in this task. So far, I've
> reinstalled a new server, configured the same IP and hostname of the failed
> one, and installed all the software. I've also fixed DRBD layer and started
> the resync of the volumes. But it's not clear to me how to proceed - I've
> found some hints online pointing to the need of manually copying corosync
> config, but they were quite old and probably obsolete. I'm using pcs as a
> shell and I haven't found a command designed to replace a node, only to add
> or remove them.
>
> It seems really strange to me that there isn't a guide, since this should
> be a very basic operation and it's quite important to know how to do it -
> HW breaks, as a matter of fact :D
>
> So I'll be very grateful if anyone can point me in the right direction.
>
> Thanks in advance, and best regards
>
>
>
> Fabrizio
>
>
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