Help! Fujitsu M2263 labeling problems (sunos 4.1.1)

[Rich Winkel]

Sunos format works fine until it attempts to write the backup label
to this disk.  The error message is:

Block 1308240 (1615/1/36) fatal non-media error (illegal request)
Warning: error writing backup label

The disk is labeled as a "SUN0669".  Following is the corresponding
entry in format.dat:
disk_type = "SUN0669" \
        : ctlr = MD21 : fmt_time = 4 \
        : trks_zone = 15 : asect = 5 : atrks = 30 \
        : ncyl =  1614 : acyl = 2 : pcyl = 1632 : nhead = 15 : nsect = 54 \
        : rpm = 3600 : bpt = 31410

The disk seems to be working properly, and the defect list apparently 
wasn't destroyed, but I'm worried about future problems.  Does anyone
have an idea what's going on here?

Thanks for any help!
rich at pencil.cs.missouri.edu
mathrich at umcvmb.missouri.edu