scrubbing-bubbles.mit.edu# ps -ef | grep 24667
    root 24667 24665  0 00:15:00 ?        0:00 /etc/athena/cleanup
scrubbing-bubbles.mit.edu# truss -p 24667
fcntl(4, F_SETLKW, 0xFFBEFC48)  (sleeping...)
scrubbing-bubbles.mit.edu# /usr/proc/bin/pfiles 24667
   4: S_IFREG mode:0600 dev:118,8 ino:2159095 uid:0 gid:1 size:23
      O_RDWR
      advisory write lock set by process 21030

scrubbing-bubbles.mit.edu# ps -ef | grep 21030
    root 21030     1  0 17:17:18 ?        0:00 /etc/athena/sshd
 candace 21038 21030  0 17:17:22 pts/25   0:00 -tcsh
    root 24460 21030  0 00:12:39 ?        0:00 detach -quiet -nozephyr candace
    root  5038  4300  0 04:08:55 pts/63   0:00 grep 21030
scrubbing-bubbles.mit.edu# truss -p 21030
waitid(P_PID, 24460, 0xFFBEAB68, WEXITED|WTRAPPED) (sleeping...)
scrubbing-bubbles.mit.edu# truss -p 24460
    *** SUID: ruid/euid/suid = 43042 / 0 / 0  ***
fcntl(6, F_SETLKW, 0xFFBEF910)  (sleeping...)
scrubbing-bubbles.mit.edu# /usr/proc/bin/pfiles 24460
24460:  detach -quiet -nozephyr candace
   6: S_IFREG mode:0600 dev:118,8 ino:2128905 uid:0 gid:0 size:0
      O_RDWR
      advisory read lock set by process 23707

scrubbing-bubbles.mit.edu# ps -ef | grep 23707
    root  5085  4300  0 04:11:01 pts/63   0:00 grep 23707
mkkangas 23707 23700  0 00:04:11 pts/28   0:00 /bin/athena/attach -Padd -P /srvd/patch /usr/athena/bin /usr/athena/etc /bin/at
scrubbing-bubbles.mit.edu# truss -p 23707
    *** SUID: ruid/euid/suid = 29090 / 29090 / 0  ***
lstat("/afs/athena.mit.edu/course/other/pclu", 0xFFBEF598) (sleeping...)
scrubbing-bubbles.mit.edu# ls /afs/athena.mit.edu/course/other/pclu
[... hung ...]