psw@wolfgang.arpa (Phil Wherry) (02/13/88)
I'm having problems with version 1.1 of Minix that I think some readers of
this light might be able to help me with. I'm using Minix on a PC-AT clone
with both a 1.2M drive and a 360k drive (these machines belong to my school)
and I would like to build a distribution that I can use on my PC-XT machine,
which has two 360k drives available.
"No problem," said I, "I'll just format some 360k disks and make filesystems
on them, them mount them in /dev/fd1 and copy files. What could be simpler?"
So, armed with a small mountain of 360k disks, I set out to do just that.
I had the /usr disk already mounted on /dev/at0 (the 1.2M drive) and I
put the 360k disk in /dev/fd1. From there, I did a mkfs /dev/fd1 360, which
executed without a hitch. Similarly, the /etc/mount /dev/fd1 /user command
did just what I thought it should.
Problems arose, however, when I attempted to copy files from my /usr file
system to the /user system (my 360k disks). After some indeterminate amount
of time, /dev/fd1 let loose with a sound that one professor likened to that
of a fire alarm. It sounded more to me like someone was determined to shift
gears on the thing without hitting the clutch, but in any case, the noise
was most decidedly NOT one of the normal clunks and buzzes that you hear
from a floppy drive.
A few more relevant details about the problem (basically the thought processes
leading up to my mental logjam):
o This happens well before the 360k disk fills up (I've never gotten
one more than half full in a single pass before this happens).
o Rebooting solves the problem temporarily, but it occurs more and more
frequently as the disk fills up.
o The 360k disk in question isn't bad. This has happened on a number
of disks, all premium-quality 360k disks formatted in the drive
being used for the copy operation.
o This happens on more than one computer, so it's not the computer or
at least unique to a particular unit.
Interestingly enough, it's possible to build a 360k disk by copying files to
the RAMdisk, unmounting /dev/at0, mounting the 360k disk in /dev/fd0, and
copy the files, then repeating until finished or tired (the latter is
guaranteed to happen first). I've built a bootable Minix via this method,
but I'm not thrilled about the idea of copying all of the tools to the
360k disks in this manner. My guess is that for some reason, Minix thinks
that the 360k disk is actually a 1.2M disk (80 tracks) and is trying to
double-step the head for each track on the 360k disk -- this would explain
why it works as it does (and doesn't work...)
Has anyone else encountered a similar problem (or better yet, developed a fix
for it?)
Phil Wherry
#pswher@wmmvs (bitnet)
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