[comp.unix.aux] Mounting SunOS filesystems on A/UX?

pfile@sprite.berkeley.edu (Rob Pfile) (03/24/91)

Hi folx,

	I had sort of a crazy idea the other day. I do a lot of file transfers
between the unix/internet world to Macs, and I usually connect a serial cable
to a sparcstation and zmodem the stuff over at 19.2Kbaud. A couple of weeks
ago, I finally got A/UX for my macintosh at home, and started formatting disks
for use with A/UX, etc, and noticing that A/UX can mount BSD 4.2 filesystems,
thought maybe that somehow I could get my mac to mount a sunOS 4.1 filesystem
in order to transfer large programs (like binaries for X, gnu stuff, etc)
fast.

	I started playing around with this today, and just tried the naive 
approach of using mount on A/UX. It did not work. Bunch of errors about not
being able to determine the type of the filesystem...I am used to the sun world
of /dev/sd1[a..g], etc, and am pretty unfamiliar with (what I assume is)
the system-Vish /dev/dsk/ type stuff. In particular, I did not know which
slice to try (the sunOS disk has a, b and g partitions) and know that these
slices probably have nothing to do with the sunOS partitions. I am particularly
curious as to why there are the "extra" slices cXd0s30, 32 in addition to
cXd0s3, and why trying cXd0s30 gave a different error: invalid file system 
type.

	Anyway, I realize that an A/UX disk is fundamentally different from
a sunOS disk given the way they are partitioned. Upon reflecting upon this
post, I realize that the slice and partition information is probably contained
in the partition map, which I assume is fixed on the disk in both cases, and
has to be read by the driver to determine where the partitions physically
reside. Trying to mount the sunOS disk referring to it as an AUX device, then
of course makes no sense (but hey, it was worth a shot)

	So, it looks like I need to write a special driver. After failing
with the mount command, I started trying to read the label off of the sunOS
disk. What I need to do is seek to cyl 0, head 0, sector 0 and read the
scsi block. How can this be accomplished given the partition problem above?
I can't remember if the raw disk devices are of the form cXd0sX or just
cXd0 which would make more sense.

	Has anyone tried this? Any ideas?

Rob Pfile
pfile@sprite.berkeley.edu