patch to du to restrict to one file-system

[Mark Levine]

If this is a recurring problem with your system (how to find out
who is using the disk space), you may find it worthwhile to just
use the quota mechanism.  Even if you don't want to enforce small
quotas, you can give all users unbounded use of the disk and
still get a report of who is using how much across logins.  And,
of course, if you do need to enforce limits on use, well, it is
designed for same.

Eleazor bar Shimon, once and future Carolingian
yba at sabre.bellcore.com