suggestions for param.h on 11/70 with V7?

[edhall%rand-unix at sri-unix.UUCP]

Right away your 64 lines eat up 64 process slots, assuming each one of
them is potentially able to be used at any one time.  Then, you need
about 4 more process slots per user at maximum load (which I hope is
considerably less than 64).  This is NPROC.  Give each of these users
about 8 inodes (NINODE) and 8 file-table entries (NFILE).  The CMAPSIZ
and SMAPSIZ should probably be increased to 100 to be conservative
(they don't take much room), though the manual is theoretically
correct.

256K (512 blocks) of swap per user should be quite generous.  I've
seen systems with less than half of this ratio which have never run
out, even though they run large multi-process programs like Ingres.

The size of your C-list should be about 15 nodes per user (I forget
what the parameter name for this is) if you have the standard
16-byte Clist element and terminal driver.

Time-callouts (NCALL) are very system-dependent, but if you use
terminal delays better make this one at least equal to the number
of users plus twenty.  If you don't, and there are no other device
drivers on the system which use them, then 20 total may be enough.

Text segments are also ver system-dependent.  Allocate one of these
per program with the `sticky-bit' set, plus one or two per user,
depending upon how many of your programs have pure texts.

Then, take it up to 48K with buffers (NBUF).  Note that both the
number 6 and 7 segmentation registers are used for other things;
7, as you say, for the I/O page, and 6 for mapping in per-process
data.  If the number of buffers is too small, you'll have to
start pruning other tables.  Inodes, files, and processes are
the three places to cut.

All I have described is for vanilla V7 UNIX.  2.xBSD systems and
others that allow kernal overlays will be different.  And I'm
sure others might disagree with some of my suggestions.  But
they should be a good starting-point.

		-Ed Hall
		Rand Corporation
		edhall at rand-unix        (ARPA)
		decvax!randvax!edhall   (UUCP)