Path: utzoo!mnetor!uunet!husc6!cmcl2!brl-adm!adm!rbj@icst-cmr.arpa
From: rbj@icst-cmr.arpa (Root Boy Jim)
Newsgroups: comp.unix.wizards
Subject: RAM disk as /dev/swap
Message-ID: <10776@brl-adm.ARPA>
Date: 10 Dec 87 22:42:47 GMT
Sender: news@brl-adm.ARPA
Lines: 26


   It is my recollection (from the good old days of real machines with 64
   or 128kb address spaces, and maybe 4meg of memory) that the real win
   came with having /tmp as ram, as everything wrote it's tmp files there
   to save memory (vi, ed, cc, mail, troff,....), and with this as a ram
   disk, you really won.

Not necessarily. As you well know, UNIX does writes when it feels like it,
and uses any available in core blocks to read from. So if a program
started and finished between /etc/update's sync's, the only disk overhead
would be that of creating and deleting a directory entry which is done
synchronously.

If you declare /tmp as a disk, you will be keeping two copies of the
most recently used blocks in core.

Of course, I defer to Ron Natalie's real world observation that it really
does help. After all, how many invocations of the above named commands
have you run in less than 30 seconds lately?

   Jason

	(Root Boy) Jim Cottrell	
	National Bureau of Standards
	Flamer's Hotline: (301) 975-5688
I'm continually AMAZED at th'breathtaking effects of WIND EROSION!!