Jenkins backups not working reliably to NFS mount

The creation of the backups appears to be failing when using the (NFS mounted) backup file system on the server. After about 8 minutes it gives this message: `SEVERE h.i.i.InstallUncaughtExceptionHandler$DefaultUncaughtExceptionHandler#uncaughtException: A thread (ThinBackup Worker Thread thread/1018519) died unexpectedly due to an uncaught exception, this may leave your Jenkins in a bad way and is usually indicative of a bug in the code` whereas if I set thinbackup to use a local directory it seems to complete in around seven minutes (Backups are about 17Gb, compressing to just under 2Gb). It only gives the first four `found x jobs in /home/... to back up` messages, of about 60 or so.

So in order to fix this and produce useful backups we'll need to resolve the performance issue on the backup drive, or backup locally and have something else move them onto the backup drive separately.

FYI @karianna

_Originally posted by @sxa in https://github.com/adoptium/infrastructure/issues/2108#issuecomment-1511219857_