Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!usc!ucsd!ucbvax!bloom-beacon!mcgill-vision!thunder.mcrcim.mcgill.edu!mouse
From: mouse@thunder.mcrcim.mcgill.edu (der Mouse)
Newsgroups: comp.sys.next
Subject: Re: File System Full?????
Message-ID: <1990Nov30.033606.26470@thunder.mcrcim.mcgill.edu>
Date: 30 Nov 90 03:36:06 GMT
References: <1990Nov28.080352.23755@msuinfo.cl.msu.edu>
Organization: McGill Research Centre for Intelligent Machines
Lines: 31

In article <1990Nov28.080352.23755@msuinfo.cl.msu.edu>, chouw@buster.cps.msu.edu (Wen Hwa Chou) writes:

> Hello, here is a real interesting case for NeXT.

> I received the report that one of our NeXT is disk full.  So I went
> out and checked it.  But the total number I've got for all the local
> files is always 200MB less than the disk space.  So where did the
> 200MB go?

> [...runaway csh and mail, corresponding to someone who has already
> logged out...]
> Again, the total space used by all the processes are only 40M also.
> We still come out 160MB short.  Since the that orphant tty session
> have been idled for 11 hours.  I decided to kill them.  Once I did
> that, boom! All the missing 200MB came back!

Once a file is open, it remains in existence until it is closed.  (If
it has any names in the filesystem, it sticks around until they're gone
too.)  So either the csh or the mail - or both - presumably had a file
somewhere open, but all its names in the filesystem had been deleted.
When you killed the processes, this reference to the file went away and
it was deleted, thus freeing the space it was occupying.

This is not NeXT-specific; all UNIX variants I know of behave this way.
I suspect everything since V7 has.

					der Mouse

			old: mcgill-vision!mouse
			new: mouse@larry.mcrcim.mcgill.edu