Potential connection loss to CERN AFS cell (retirement of old VLDB servers)

(This is a site-specific operational issue but we hope to give other AFS site admins a heads-up for any user support issues. Apologies if you are not concerned at all.)

Dear all,

In the next week, CERN will turn off the last two original AFS CERN VLDB servers (or rather, the machines using their IP addresses). For reasons related to our network structure and IP allocation, we could not keep the old IPs when retiring the current server generation.

AFS clients still using (only) these IPs will no longer be able to connect to the CERN AFS cell.
We have attempted to get the central CellServDB updated ahead of this change (first with new IPs, then to use (only) DNS for "cern.ch"). However, CellServDB is shipped by various distributions, and anyway only considered at (Linux) client start.


How to check whether a particular AFS client is affected:
$ fs getserverprefs -vlservers | grep -E 'afsdb[0-9]+.cern.ch'

- if the output only mentions afsdb1{1,2,3,4}.cern.ch, the configuration is DNS-based and correct - no issues expected.
- if the output mentions a mix of afsdb{1,2}.cern.ch and afsdb1{1,2,3}.cern.ch (the current central CellServDB config), this client will switch automatically to our new servers, possibly after a short hiccup - no major issues expected.
- if the output only has afsdb{1,2}.cern.ch, this client will not be able to connect to CERN.CH in the future.

Our recommendation is to use DNS - CellServDB should have an entry for the cell but no IPs:
>cern.ch                #European Laboratory for Particle Physics, Geneva
/>(next cell info here)

Regards,
Diogo Castro
on behalf of the CERN AFS service