I have been having troubles with kernel dumps on the machine at work (a
486 box). They consistently overwrite the bootblocks on the harddisk
where the swap partition is. (Thank ghod not the disk label). This is
easily repaired with a disklabel -B wd0 after booting from floppy, but
it is still a pain in the a**.

# /dev/rwd0a:
type: ST506
disk: ide0
label: 
flags:
bytes/sector: 512
sectors/track: 56
tracks/cylinder: 15
sectors/cylinder: 840
cylinders: 989
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0           # milliseconds
track-to-track seek: 0  # milliseconds
drivedata: 0 

5 partitions:
#        size   offset    fstype   [fsize bsize   cpg]
  a:    32760        0    4.2BSD     1024  8192    16   # (Cyl.    0 - 38)
  b:    32760    32760      swap                        # (Cyl.   39 - 77)
  c:   830760        0    unused        0     0         # (Cyl.    0 - 988)
  d:   830760        0    unused        0     0         # (Cyl.    0 - 988)
  e:   765240    65520    4.2BSD     1024  8192    16   # (Cyl.   78 - 988)


I first thought it was only a problem with -current kernels (I had the
problem with several) but it just happened to my 1.0 kernel (which
froze after I tried to use the SCSI tape drive, recognised as aha0 targ
0 lun 0: <WANGTEK 5150ES SCSI FA1501 A> SCSI1 sequential removable,
with density 16 (150 M) instead of the default 15 (120 M). What happened
was 100s of messages "st0(aha0:0:0): illegal request" in the xconsole
window, and a freeze.

ObNonI386: kernel dumps used to work on my Amiga (a year ago).

So basically I have two (most likely unrelated) questions:

1. Anyone else having trouble with kernel dumps overwriting bootblocks?
2. Why does the tape drive default to 120M per 600 ft tape (density
   code 15, I think 15 tracks), instead of 150M (density code 16, 18
   tracks), and why go I get "illegal request" errors if I try to use
   the tape to capacity? (... and Linux did it right...)

-Olaf.
--
HAVE *YOU* EXPORTED A CRYPTO SYSTEM TODAY? --> http://dcs.ex.ac.uk/~aba/x.html
-------------------------------------8<-------------------------------------
#!/usr/local/bin/perl --#export-a-crypto-system sig, Diffie-Hellman 2 lines:
($g,$e,$m)=@ARGV;$_=unpack('B*',pack('H*',1&length$e?"0$e":$e));s/^0+//;
s/1/0lG*lm%/g;s/0/d*lm%/g;print `echo 16i\U$g"\nSG$m\Esm1Io$_"p|dc`
-------------------------------------8<-------------------------------------
___ Olaf 'Rhialto' Seibert    rhialto@mbfys.kun.nl         What's the use of
\X/  racism if you can't even see if a person belongs to your abhorred kind?