Is there a way to find out the directory/disk location a process was started from? I am aware of the /proc mount but not really where to look inside of it.
The /proc way would be to inspect the exe link in the directory corresponding to the pid.
Let's take an example with update-notifier:
Find the pid, which is 15421 in this example:
egil@gud:~$ ps x | grep update-notifier
2405 pts/4 S+ 0:00 grep update-notifier
15421 ? Sl 0:00 update-notifier
Look up the symbolic link:
egil@gud:~$ file /proc/15421/exe
/proc/15421/exe: symbolic link to `/usr/bin/update-notifier'
