This usually means the ‘kerberos ticket’ for your user has expired. Kerberos tickets allow the system to know what your user is allowed to do, for security, they automatically expire at a set time after you log in. Most of the time these tickets are automatically renewed while you’re working, but they can expire during long copy commands.

You need to take two steps to avoid timeouts. * Firstly, you will periodically need to renew your Kerberos authentication ticket, which controls your access to '/rdw' and expires after 10 hours. The 'krenew' command will do the renewal automatically for up to a week. * Secondly, to stop your process being killed if you are logged out, run it within a tmux session, then detach from your login. You can reattach later if necessary. An example session might look like this:

• Start a new tmux session: tmux
• Use krenew to ensure you have updated kerberos tickets, then send the rsync command into the tmux session

$ tmux
$ krenew -v -- bash -c 'rsync -trlv --inplace /nobackup/myuser/ /rdw/myshare/ >> mylogfile'

• Detach the tmux session with <Ctrl-b d>
• If necessary, start tmux again and attach to your previous session: tmux attach