Hard Disk problems

[Matthias Urlichs]

First, if you get a stupid error message saying "More data than device
expected" when you try to dp the drive, then you need to run Tony's "Fix
Error Page" program under MacOS before doing anything else.
This applies mostly to Syquest cartridges (you'll have to modify all of
them as the parameters are stored on the cartridge), but some hard disks are
also affected.

In comp.unix.aux, article <1991Apr1.231933.14564 at am.dsir.govt.nz>,
  Tony Cooper writes:
< 
< The way to mount an HFS volume is to mount it under MacOS first. Then, and
< only then, boot A/UX. A/UX will only mount the first HFS partition on a
< disk. And then ONLY when it was mounted under MacOS first.
< 
Actually, only if the appropriate MacOS driver was installed and operational.

That's important when using Syquests and your MacOS driver doesn't
understand the partition map. Unfortunately, some of these older Syquest
drivers will also fail to look whether the bus is busy when they check for a
cartridge, the effect of which is that A/UX Startup hangs while displaying
the "Checking" or "Loading" status messages.
They will also lock the drive's eject mechanism. Time to get a driver update.


< [ using dp ]

The most common problem seems to be that the physical size is correct but the
logical size is zero. The fix is obvious:
[ dp hard disk, print map, find HFS partition(s) ]

c N  (with N the first HFS partition map entry's number)
) XXX (with XXX the partition's physical size)
p      (check that you did everything correctly)
qwq     (end editing, write map, end dP)
< 
< If the partition table
< is wrong then your drive formatting software is out of date.
< 
Be aware that it'll probably become bad again the next time you use your
regular partitioning software.

< dd in=/dev/rdsk/cxd0s30 count=1 | od -c
Better (with x your SCSI ID):
% dd in=/dev/dsk/cxd0s30 bs=512 skip=2 count=1 | od -c | more
The first two letters are BD (for "Big Disk", or HFS).
This will look OK even if you never installed a System on that partition.

< [ HFSMount ]

Will that beast work with multiple HFS partitions per drive?
-- 
Matthias Urlichs -- urlichs at smurf.sub.org -- urlichs at smurf.ira.uka.de     /(o\
Humboldtstrasse 7 - 7500 Karlsruhe 1 - FRG -- +49-721-621127(0700-2330)   \o)/