This article is from a FAQ concerning SCO operating
systems. While some of the information may be applicable to any OS,
or any Unix or Linux OS, it may be specific to SCO Xenix, Open
There is lots of Linux, Mac OS X and general Unix info elsewhere on
this site: Search this site is the best
way to find anything.
Basically, they start at 64 (the major device number is 1) and
go up by 64 each time you run mkdev
hd. Don't expect them to be in the same order as your SCSI IDs
for the drives unless that's the order you added them in. Also, if
you being running mkdev hd but do not complete the process, it will
generally already have assigned the next number; the next time you
run mkdev hd, it will add another 64 even though you aren't
actually using the last drive you started to create. This isn't a
problem; it just looks weird.