Add missing drive name to taped process names

At the moment, the process name of the maintenance process is set to cta-tpd-maint. If multiple taped services are running on the same machine, it means that the process name cannot be used to uniquely identify which taped service it belongs to. A similar problem appears for the master process, which is cta-tpd-master.

This is particularly problematic for telemetry, where the process name will (need to) be used to uniquely identify a process on a given host.

Additionally, it is also problematic for operations. Executing ps -u cta allows operators to see the processes and potentially kill one of them if needed. However, if multiple taped processes are running, there is no distinction between the maint/master processes.

For reference, here is what is shown on a tapeserver with 2 drives actively transferring:

[root@tpsrv640 ~]# ps -eo pid,user,comm | grep cta
 726964 cta      cta-rmcd
3262030 cta      cta-tpd-master
3262033 cta      cta-tpd-maint
3262257 cta      cta-tpd-master
3262259 cta      cta-tpd-maint
3702349 cta      cta-tpd-F10B1S2
3708150 cta      cta-tpd-F10B1S1

Simply appending the drive name is not possible, as there is a 16-byte limit to the process name.

We should make sure this is consistent. Doing so is cleaner and allows us to better identify the processes.

---

Accepted Proposal

To close down the discussion, we are going for proposal 3:

F10B1S2-parent
F10B1S2-maint
F10B1S2-drive

There will be a check on the drive name part to ensure it remains below 13 characters. This way, we still keep a single letter from the postfix allowing the process to be identified. The check will produce a warning (not an error), as we don't want to break existing deployments for something that does not concretely affect any functionality.