Question on Partitioning Hard drive

[sramtrc at windy.dsir.govt.nz]

In article <1991Jan17.231709.8562 at zeno.mn.org>, andy at zeno.mn.org (Andy Joe) writes:
> 
> I have several questions concerning AUX 2.0 and partitioning a
> hard drive.  Firstly, I am wondering if there is any problems (pros
> or cons) with setting up a 450 meg partition for the Root & Usr,
> a 18 meg swap, and a 3 meg Eschatology.  I am actually running with

My personal preference is to have separate root and usr partitions. The
root partition is not written to very frequently and so you can fill it
right up to, say, 99% full instead of 90%. That way you get an extra 9%
disk space. I used to recommend a seperate /tmp partition but that was
in the old days of the svfs filesystem which used to keep inodes separate
from files. The ufs filesystem does not have this problem since it spreads
the inodes out over the disk. Another possibility that I have not tried
since it involves a lot of work is to mount the root partition read-only.
That gives a margin of safety and means that you only have to do one 
backup since nothing changes.

A good reason for partitioning drives is to speed up the seek time. I have
a ZBR disk which means the outside tracks are read faster. So I have the
swap partiton first, then root, then /tmp partition, then 3 usr partitions,
then 4 MacOS partitions. I do my active work on the usr partition closest
to the root, and keep the others for lesser used stuff. So most of the time
my drives seeks over 30% of the disk which brings the average seek time
down to 5 ms. When I run MacOS the seek time is still 5ms since I use
about 30% of the disk there. Again the most active partitions are together.
> 
> partition.  Therefore as stated above, I do not have a auto-recovery
> partition (who says you need on anyways, huh?? :-> ).  (I have spoken

You don't need one. Making backups is for pessimists.

> I would like to know if it is possible to use 'dp' to modify the partition

dp will let you modify the partitions to anything you like, even to create
partitions that overlap or have the wrong type etc. So it can do everything
you like plus more. You just have to make sure you know what you are
doing. A dose of RTFM (including Inside Mac V) is pretty important.

> My last question concerns the 100 meg Mac partition that I created
> on the WREN V.  It is visiable when I am running under the Mac OS, but
> when I boot up AUX, only the original 80 meg Quatum drive (Mac partition)
> and the root folder shows ups.  Is there some magic I have to perform or
> do I have to RTFM?

I don't think there is a FM on this one. I don't know why it doesn't show
up. As long as it was mounted before you ran A/UX Startup and it is the
only HFS partition on the drive it should show up under MacOS under A/UX.
Read some earlier news articles because I vaguely remember someone offering
advice that fixed someone's problems in this regard. Note that Apple only
support one HFS partition per drive. There is third party software to
support more than one partition so if you want to create more than one
you can go ahead.

If all this proves to be too much trouble for you I will exchange your
Wren V for my Quantum 80. It is an official Apple drive and is already
partitioned and boots quite well. And if you use only two tracks you
can get the average seek time down to a millisecond.

Cheers,
Tony Cooper
sramtrc at albert.dsir.govt.nz