Subject: Re: sysstat bufcache display.
To: Hubert Feyrer <hubert.feyrer@rz.uni-regensburg.de>
From: Simon Burge <simonb@netbsd.org>
List: tech-userlevel
Date: 11/01/1999 14:35:45
Hubert Feyrer wrote:

> [ sysstat bufcache changes ]
> 
> Cool thing!
> 
> Two questions:
>  - shouldn't the "Total" Bufsize kB be equal to the ammount in the first
>    line ("There are ...")?
>  - What is "Valid kB" over "Bufsize kB" - Actually used space vs. Size of
>    the buffer? (If so, could the "Valid kB" be changed to "kB in use" or
>    something a bit more descriptive?)

Would the lame answer "I'm not sure :-)" be ok?

For Q1, I guess not all buffers are actually allocated to vnodes.  I
guess things like inodes, super blocks and indirect blocks are taking up
the rest of the space.  I haven't got the daemon book handy and actually
wrote this back in April then forgot all about it :(

For Q2, this probably makes sense.


For those that are interested, this type of display is available with
the Ultrix "monitor" command, although the buffer cache structures have
changed a lot between bsd4.2 and now and the "monitor" code was pretty
much useless...

Simon.