sticky bits ?

[Fred Christiansen]

(our environment:  System V Release 2 on VAX and 68000-based systems)

Setting the sticky bit causes the loadable image of a program to go
to swap on its first invocation and stay there, even after the program
terminates execution.  This speeds up the loading of subsequent invocations
of the same program.  This is handy for commonly invoked programs.
	While benign, it is of little use to set the sticky bit on a program
that will be nearly continuously in use (such as init(1m), getty(1), or sh(1))
since, by the nature of its usage, it is normally in this "state" anyhow.
	The recommendation of the SysV Administrator's manual is to run
the system activity package and observe the 20 or so most commonly invoked
programs, then set the sticky bit on these.  The caveat here, tho, is to
scale that number (20) up or down depending on the amount of swap space
allocated.  (We had one panicking customer call for help when he kept
running out of swap space.  Turns out he was filling up his swap space
by having the sticky bit set on too many programs.)
-- 
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Fred Christiansen, Networking Software, Motorola Microsystems, Tempe, AZ  85282
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