From: ace3@quads.uchicago.edu (AA Acero (Tony)) Subject: [Q] fdformat / fdprm / setfdprm (afio) Date: Tue, 16 Mar 1993 15:34:52 GMT
What does it take to get Linux to support non-standard disk formats? I am
particularily interested in the two 'higher capacity' formats in fdprm:
1440/1200 and 1680/1440. 1440/1200 is only partially complete in my copy
of fdprm, and the 1680/1440 entry fails as explained below. I have
retrieved fdformat18 (the DOS program (in Pascal ugh!)) but haven't been
able to make much sense of it yet.
Also, is there any way to get fdformat/Linux to ignore the missing hole in
1MB (720K) 3.5" disks, when attempting to format them at 1.44M? Fdformat
goes through the format phase happily, but when it tries to verify it fails
with an I/O error similar to the one for attempting to format a high
density 3.5" 1680K. (I'm assuming that this I/O error is related to the
missing hole, please see below)
When I try:
#Please note 'fdformat /dev/fd0h1200' and 'fdformat /dev/fd1H1440' both
#work fine
#Attempt to format high density 3.5" floppy to 1680K
setfdprm /dev/fd1 1680/1440 # b: is a 3.5" floppy
fdformat /dev/fd1
Double-sided, 80 tracks, 21 sec/track. Total capacity 1680 kB.
Formatting ... done
Verifying ... read: I/O error
#Attempt to format low(?) density 3.5" floppy to 1440K
fdformat /dev/fd1H1440
Double-sided, 80 tracks, 18 sec/track. Total capacity 1440 kB.
Formatting ... done
Verifying ... read: I/O error
I'd been thinking of working on this since last summer, but it's suddenly
taken on particular urgency because of the recent release of 'afio' --
thank you Dave Gymer! Basically, afio allows you to do multi-volume
archives with individual file compression (so that if one portion of your
backup is corrupt, the rest of it is not worthless). If one of those
higher capacity formats could be made to work, it would mean a savings of 1
disk in 5 during a backup (as well as having that much more space on an
emergency root disk!)
As a reward for reading this far, here's the commandline to backup your
root partion using compression and multiple archives (it should save you
the 1/2 hour I spent digesting the man page :-) :
# /dev/fd0 is a high density 5.25" drive
# '-xdev' prevents find from 'descending dirs on other filesystmes'
find / -xdev | afio -ozFKZ -b 15k -s 1200k -L /tmp/back.log /dev/fd0
Many thanks for any help/suggestions!!
-- Tony Acero \ "If I have seen further, it is because I have stood /U Chicago ICS: LLama \ on the shoulders of giants." Isaac Newton /chem grad 'a coy tenor'\____________________________________________________/ '93? :-) ace3@quads.uchicago.edu | (312)702-8214 (work) | (312)752-5464 (home)