Xylogics 451 with Fujitsu M2372K and M2351

[dupuy at cs.columbia.edu]

You problem is that the 451 controller can only deal with 4 types of disks
at once.  It keeps track of each type by a number (from 0 to 3) which
corresponds to a particular geometry.  The old Sun standalone diag
program, and the new Sun format program both assign disk types to numbers
in a fixed and arbitrary manner (i.e. M2351 -> 0, M2361 -> 3, etc.).  Your
error message:

	xy0 and xy1 are of the same type (0) but with different geometries
	xy1: cannot read label

indicates that both have been assigned the type number 0.  All you have to
do is to reassign one of them to use a different type number.  With 4.0
format, this would be a fairly easy thing to do; all you would need would
be to cobble up the following entry for /etc/format.dat:

disk_type = "Fujitsu-M2372K" \
        : ctlr = XY450 : fmt_time = 4 \
        : ncyl = 743 : acyl = 2 : pcyl = 745 : nhead = 27 : nsect = 67 \
        : rpm = 3600 : bpt = 40960 : bps = 600 : drive_type = 2

and relabel the disk using format (being sure to use the exact same
partitions as before).  With 3.5, it's a bit trickier.  You need to bring
up the standalone diag, and when it asks you the disk type, say (other).
It will then ask you a whole slew of questions, the answers to which are
in the above format.dat entry.  Be sure to specify the same partitions as
before, and relabel the disk.  After this, all your problems should cease.

Be sure to do a full backup of the disk before trying this, just in case.

@alex