inexplicable slowness

[Lee Casuto]

One possible reason is that your file system(s) are nearly full with
the most recently accessed files being the furthest away form the
heads. If this is the problem, the solution is to back up the file
systems sorted on access (modification) time. Do a mkfs the file system.
Restore the files on the new file system. This has been reported to
increase performance dramatically. 

Lee Casuto
...ucbvax!hpda!lkc