Subject: Re: new disklabels - part2
To: Darren Reed <>
From: Greywolf <>
List: tech-kern
Date: 09/21/1999 10:43:16
On Tue, 21 Sep 1999, Darren Reed wrote:

# Why 0 ?  At present it's c or d, is it not ?

I think he meant partition _offset index_ 0, i.e. 'a'.

# Also, why does the disk label structure need to change ?  To be frank, having
# to edit the disk label so you can mount DOS partitions is fucked.  If wedges
# get around this then wedges should be used.  The current device name space
# used for disks (<disk-type><number><partition>) is too small.  For PC's, at
# least, you should be able to unambiguously refer to each fdisk partition
# separately.  Either one of two solutions is required: (1) the FreeBSD
# approach of <disk-type><number><fdisk-partition-reference><partition>,
# i.e. wd0a becomes wd0s3a or (2) the Solaris approach, which includes the
# `full address' of the disk (c0d0p0 for the partition, c0d0s0 for the UFS
# bit).

Oh, please let's not go to the /dev/dsk/c0d0s0 graveyard.  "c0" tells
me nothing.  I'd rather know the disk-level interface (sd &c.).  If I
have a machine with sd* at scsibus? target ? unit ?, and xy* at
xyc? target ? unit ?, and things come back as /dev/dsk/c0t3d0s2 (ICK!
Hacch-tooey!), this hides information from me, which does naught for
me but to waste my time.

But that's my opinion.

I'll go read that wedge proposal of mycroft's and it might well
change my initial evaluation below:

We need some sort of algorithm by which we allocate and name alternately
based partitions (AmigaOS, TOS, MS-DOS, whatever); I think it should
be something that migrates reasonably well across platforms; i.e.,
it should not appear as /dev/disk/sd0a on intel and appear as
/dev/dsk/c0t3d0sk (ICK!  Hacch-tooey!) on a different platform.

# All that then remains is being able to `wire down' the reference
# to where the disk and controller are so you can support the old naming
# convention of 'sd0a' as well as adding/removing hard drives above and below
# the SCSI id of the root disk, without disrupting fstab.
# Darren

	"Just click on the START button and your journey to the Dark Side
	 will be complete!"