the 10% factor

[jim frost]

BACON at MTUS5.BITNET (Jeffery Bacon) writes:
>    How does one learn this stuff? I RTF(Sun)Ms, but it didn't help that much.
>Or was I looking in the wrong place?

Get a copy of "The Design and Implementation of 4.3 BSD UNIX",
available at any good bookstore near you.  It explains how the
filesystem was implemented and why they recommend the 10% buffer.
There's also an article in the USENIX Computing Systems Journal
(Volume 2, Number 3, Summer 1989), "Heuristics for Disk Drive
Positioning in 4.3BSD" which describes how to tune the BSD hp disk
driver (and some implementation issues) which you might find
interesting.

The BSD book, and the System V counterpart by Bach, is very
enlightening if you really want to know the how and why.  Both of them
will require a bit of operating systems understanding before you delve
into them.  Both of them are a lot better if you have source to poke
at, too.

Several of the major operating systems classbooks devote substantial
space to UNIX, both System V and BSD, which might be a better place to
start since they're more general.  I've lent almost all of mine out so
I can't make particular recommendations right now.

jim frost
software tool & die
madd at std.com