A problem with corrupted directories

[David Hinds]

Every now and then, a system directory on our Iris gets corrupted by an
entry for a non-existent file.  I haven't seen any pattern to what gets
corrupted when.  At the moment, /mbox is non-existent, as is a file used
by our incremental backup scripts to save 'bru' listings.  These are
very annoying - is there any way to get rid of them without stopping the
system and doing an fsck?  They can't be rm-ed or unlink-ed.  This may
sound impossible, but sometimes they seem to disappear of their own accord
during the course of normal operations.  At least, I've never figured out
how to get rid of one, but I remember some that don't seem to exist any
more.  As drastic solutions, are there any ways in Unix to change the
attributes of a file to make it a directory, or vice-versa?  Or is there
a way to just edit a raw directory file?  As I understand things, all I
should have to do is change the I-node field of the bogus directory entry
to point to a real file, and then just delete the link.

 -David Hinds
  dhinds at cb-iris.stanford.edu