Berkeley file system tuning

[Rahul Dhesi]

In article <310 at sagpd1.UUCP> banderso at sagpd1.UUCP (Bruce Anderson) writes:
>First, I gather that using multiple disk sections is supposed to
>increase speed...

I've heard this said, but I don't see why breaking up a disk into
pieces will speed up access.  The only exception I can see is the rare
case when you have a big partition containing files that are almost
never accessed.  If this partition is at the end of the disk the disk
head almost never has to travel that far.

The main (4.3BSD-specific) reasons for having multiple disk partitions
are:  (a) dump and restore work on entire partitions, so the smaller a
partition the more flexible your backup procedures can be;
(b) filesystem parameters can be individually adjusted for partitions
in case you want to use different block sizes etc.; (c) to do swapping
on a disk you have to have a partition dedicated to that;  and (d) you
can protect the rest of the disk from filling up by giving a directory
like /usr/tmp (or /a/crash :-) its own filesystem.

I think the *most* popular reason for having disks partitioned in a
certain way is because that's how the operating system was configured
when you got it and it's too much trouble to change it.  That certainly
is why we have our disks partitioned the way they are.