> >disklabel -R /dev/sd1 MCA  (MCA is included at the bottom)
> sd1: no disk label

> disklabel: warning, unused partition c: size 310352 offset 0

That's disklabel's way of saying that the `N' in `N partitions:' should
cover the _range_ of partition definitions that follow, even if omit
some in between.  In this case, N should be at least 3.


> disklabel: ioctl DIOCWDINFO: Label magic number or checksum is wrong!

On the sparc, disklabels are kept compatible with SunOS labels. This
means that partition sizes and boundaries must be a multiple of the
number of cylinders specified in the label.

In your label the numbers do not match: 64 * 8 * 606 != 310352.
Using size 310272 should work.


> MCA:
> # /dev/rsd1c
> type: SCSI
> disk: SCSI disk
> label: optical
> flags:
> bytes/sector: 2048
> sectors/track: 64
> tracks/cylinder: 8
> sectors/cylinder: 512
> cylinders: 606
> total sectors: 310352
> rpm: 3600
> interleave: 1
> trakskew: 0
> cylinderskew: 0
> headswitch: 0    #milliseconds
> track-to-track seek: 0    #milliseconds
> drivedata: 0
> 
> 2 partitions:
> #    size    offset    fstype    [fsize bsize    cpg]
>     a: 310352    0    4.2BSD    0    0    0
>     c: 310352    0    unknown