[Samba] ctdb and AllowMixedVersion

[Sibiller, Ulrich]

Hello *.

we are using ctdb to export a Spectrum Scale filesystem via nfsv3 (kernel nfs, not ganesha, not Spectrum Scale CES). We have four nodes that are members of the ctdb, serving 8 IPs in two networks (4 in each). The systems have been setup with RHEL8.3, using the provided ctbd 4.12. Updating those systems to RHEL8.4 reveals that Red Hat switched ctdb to 4.13 so the ctdb on an updated node ceases to work together with the others still having ctdb 4.12.

ctdb offers AllowMixedVersions to disable the version check but at the same time discourages its use: https://wiki.samba.org/index.php/Upgrading_a_CTDB_cluster

As we are NOT using samba on these nodes but only nfsv3 I wonder if using AllowMixedVersions might be tolerable in this scenario. 

Besides, in a 2017 discussion on samba-technical plan for a rolling update feature are mentioned once the databases "have settled" (https://lists.samba.org/archive/samba-technical/2017-May/120760.html). So what's the current state of all that?

Thanks,

Uli