command cache and io priority

[Noah McNallie <n0ah%n0ah.org@localhost>]

Recently after configuring process scheduling priority and packet 
scheduling priority, i tested nice with simply tar -zxvf of gnusrc, i 
was amazed at what i assumed was a system that could take heavy load and 
still respond.

- operating systems that i know of seem to have a command cache, even 
under heavy disk io load. if one where to say commit 'uname -a' it would 
take perhaps 2 seconds to respond, though the next time it would respond 
fairly instantaneously. NetBSD does not seem to be doing that, the 
second go was just as slow; tested numerously

- despite this, i feel there would have to be an io scheduler  in any 
adequate operating system. linux i found has 'ionice' as part of their 
cfq system so i'm assuming netbsd has this feature also, please correct 
me if i'm wrong.

this is a sun4u system

n0ah