[Gluster-users] Gluster rolling upgrade samba 3.6 to 4.1

[Federico Nebiolo]

Dear Gluster users,

we are currently running a 12 nodes Gluster cluster, with CTDB on top
and Samba 3.6 (installation was performed with RHGS3.0).
We're currently running into issues when trying to perform a rolling
upgrade to Samba 4.1 to one of the nodes, while the others are still
running.

TDBs are shared among all nodes through CTDB, and Samba upgrade brings
up some incompatibilities, at least for registry which changed format
from Samba 3 to 4.

When one out of 12 nodes is upgraded, other nodes fails to load
correctly, as in bugs
- https://bugzilla.samba.org/show_bug.cgi?id=10314
- https://bugzilla.redhat.com/show_bug.cgi?format=multiple&id=832732

We understand downgrades are not supported, but this is not our case,
since we have to keep both versions running for a while, sharing
information through CTDB.

In addition, please consider we're not using registry for
configurations at all, so this specific TDB is empty and useless,
though it prevents samba3 to load successfully.

Which is the correct approach for an upgrade to Samba4.1 keeping
services up and running on a cluster?

Many thanks