csh hiccups

[Michel Fingerhut]

>From time to time (i.e., several times a day), a command started from csh
on our 5820 (DEC/RISC Ultrix 4.0) takes 15-30 seconds to start, regardless of
the load average of the machine.  A "ps axl" on the controling terminal shows
it's actually the csh which is in disk wait, with funny flags (some digits
missing):  in the following output it's the last line.

      F UID   PID  PPID CP PRI NI ADDR  SZ  RSS WCHAN STAT TT  TIME COMMAND
11008001   0  4281   222  2   1  0 2bdf  60   48 5f05c I    p2  0:38 rlogind
1180c001  70  4282  4281  0  -1  0 2fd7   0    0  4314 D    p2  0:00 -csh (csh)
10008021   0  5543  4282  0  25  0 2d32 232  188       T    p2  0:04 -u (csh)
   9001  70 10143  4282  1  -5  0 3030 368  284  c224 D    p2  0:09 -csh (csh)

Any clues, help?  It is rather annoying to have to wait 30 secs for an ls of
a directory on the local disk containing 4 files on a machine with load avg of
1.5 and presumed to work at 35 MIPS.