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From: ciemo@bananapc.wpd.sgi.com (Dave Ciemiewicz)
Newsgroups: comp.sys.sgi
Subject: Re: /debug directory -- what is it?
Message-ID: <1990Oct2.003853.25519@relay.wpd.sgi.com>
Date: 2 Oct 90 00:38:53 GMT
References: <901001113629.21202546@FEDC06.FED.ORNL.GOV>
Sender: news@relay.wpd.sgi.com ( CNews Account )
Reply-To: ciemo@bananapc.wpd.sgi.com (Dave Ciemiewicz)
Organization: sgi
Lines: 43

In article <901001113629.21202546@FEDC06.FED.ORNL.GOV>, RUITERJR@FEDC06.FED.ORNL.GOV ("To Thine Own Self be True.") writes:
|> Hello all, 
|> 
|>       What is the /debug directory for?  I've looked through the
|> manuals and can't find anything on it.  Seems its taking up a rather
|> large portion of our disk space, but I've never seem much of it used.
|> 
|>       Anyway I can reduce its space (or is this even desirable?) ?
|> 
|> Thanks
|>  Jason Ruiter
|>  ORNL, FED
|>  (615) 574 1308
|>  ruiterjr@fedc04.fed.ornl.gov

Here we go again . . .  :^) /debug is an artificial filesystem interface to
the processes running on your IRIS.  The size of /debug represents your total
virtual memory of your system which is real memory + the size of your swap
partition.  In a way, it is consuming real disk space, however, without the
disk space set aside for your swap partion, you'd be very limited to the size
and number of processes you'd be able to run on your system.  In otherwords,
don't go messing with /debug or your swap partion unless you know what your
doing.  /debug is not really stealing any diskspace from / or /usr.

So what's /debug good for, you might ask?  Well, /debug provides a convenient
mechanism for manipulating processes as though they were files.  This interface
makes writing and implementing a debugger like dbx easier.  Note, if you
unmount /debug, you will not be able to run dbx.

/debug is similar to /proc which is being introduced in AT&T's System V.4.
You'll be seeing more of /proc (/debug) on other vendors systems as /proc
is adopted as a standard.  Silicon Graphics just happened to do something
like /proc sooner so we could better handle multiple process debugging from
a single dbx session.

For fun, you can do an "ls -l /debug" and a "ps -e" and you'll see that
the process ids correspond.

At the very least, you're just seeing what has been previously hidden on
just about every vendor's virtual memory workstation -- the swap partion.
Don't worry about it.

						--- Ciemo