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