Ram disks

jdi at psuvax.UUCP jdi at psuvax.UUCP
Thu Jul 28 11:39:16 AEST 1983


	Here at PSU, we have an 11/34A which, although running a very nice
(local 4.1BSD compatible) version of UNIX, has one problem:

	it is s.......l.......o.......w........

	In an attempt to remedy that situation we have tried buying a $1500
2K cache memory.  Wham.  $1500 down the tube.  Speed improvement: maybe 5%.

	Basically we have figured our problem to be this: Unix uses disks.
(notice the 's').  In fact, it uses lots of disks.  As many as possible.  It
eats them for breakfast, lunch, and dinner.  Unfortunately, our budget
is something around the level needed to buy a floppy drive, so we have not
had the opportunity to buy a 890 GIGI-byte drive like all you other rich
people.

	And thus we come to the real subject of this acticle, Ram Disks.  Our
local system-god (typical hacker, large, brilliant, erratic, speaks only C..)
saw an add in a recent computer magazine, which he promptly misplaced, for
something called a Ram-Disk.  Doubtless all you CPM type people already know
that a Ram-Disk is a bunch of high-speed ram (1 MEG or more) in a box, which
is designed to look like a disk drive to the cpu.  Obviously in UNIX this
would be a great device!  Imagine, swap a 100K program in 1 second!  Imagine
(supposing you have enough ram to fit /tmp on too..)  vi'ing a file and having
it start up instantaneously.  (Yes, vax people, I know it already does on an
11/780, but on an 11/34A.....)

	And so I began purusing magazines in search of this mythical dragon-
slayer.  To no avail.  I guess rich business types use VMS, which only needs
one disk (but then we all know how (cough, cough) Nice VMS is!).  And so I
decided to see if any of you net.people might know anything about Ram-Disks.

	Please respond.  Right now when our system use goes up our only RK07
starts shaking so bad it moves it across the floor and throws things off
itself like a raging demon.  (I always did let my Dnd roots take hold of me.)


	Personally I think "Thanks in advance" is about as cute a phrase as
	such favourites as "peachy keen" and other such grade-school vocabulary,
	so I don't think I'll use it.

		-- John Irwin
		   The Pennsylvania State University

		   {burdvax, allegra}!psuvax!jdi



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