In message <0f3af5e6dd6469d004a35dcfcdc175da@crypticide.com>, Alec Muffett writ
es:
>

>
>Um, yes, and to do that requires me to understand how to *achieve* 
>that, specifically it requires me to understand the apparent disjoint 
>between the cylinder numbers reported by fdisk from the perspective of 
>the BIOS, and the cylinder numbers from the perspective of NetBSD.

Disk geometry questions are second only to X configuration in confusing 
me when setting up NetBSD systems.  Now that X 4.4.0 does a better job 
auto-probing, I may have to reverse the order....
>
>What I think I am learning from this thread is that NetBSD is not very 
>happy with talking to NetBSD (any?) partitions that exist outside the 
>scope of its main partition.

No, that's not true.  Most of my NetBSD machines have a partition label 
pointing to the Windows fdisk slice.  Here's one example:

Disk: /dev/rwd0d
NetBSD disklabel disk geometry:
cylinders: 484406, heads: 16, sectors/track: 63 (1008 sectors/cylinder)
total sectors: 488281250

BIOS disk geometry:
cylinders: 1023, heads: 255, sectors/track: 63 (16065 sectors/cylinder)
total sectors: 488281250

Partition table:
0: Dell PowerEdge Server utilities (sysid 222)
    start 63, size 128457 (63 MB, Cyls 0-8)
1: OS/2 HPFS or NTFS or QNX2 or Advanced UNIX (sysid 7)
    bootmenu: Windows
    start 128520, size 40965750 (20003 MB, Cyls 8-2558)
2: CP/M or Concurrent CP/M or Concurrent DOS or CTOS (sysid 219)
    start 482496210, size 5767335 (2816 MB, Cyls 30034-30393)
3: NetBSD (sysid 169)
    bootmenu: NetBSD
    start 41094270, size 441401940 (215528 MB, Cyls 2558-30034), Active


# disklabel wd0
# /dev/rwd0d:
type: unknown
disk: Maxtor 7Y250M0 
label: 
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 16
sectors/cylinder: 1008
cylinders: 484406
total sectors: 488281250
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0           # microseconds
track-to-track seek: 0  # microseconds
drivedata: 0 

16 partitions:
#        size    offset     fstype [fsize bsize cpg/sgs]
 a: 438255216  41094270     4.2BSD   1024  8192 46664  # (Cyl.  40768*- 475545*)
 b:   3146724 479349486       swap                     # (Cyl. 475545*- 478666*)
 c: 441401940  41094270     unused      0     0        # (Cyl.  40768*- 478666*)
 d: 488281250         0     unused      0     0        # (Cyl.      0 - 484406*)
 e:    128457        63    unknown                     # (Cyl.      0*-    127*)
 f:  40965750    128520       NTFS                     # (Cyl.    127*-  40768*)
 g:   5767335 482496210    unknown                     # (Cyl. 478666*- 484388*)
# 


		--Prof. Steven M. Bellovin, http://www.cs.columbia.edu/~smb