[rescue] sformat a large drive under IRIX 6.5

[Sheldon T. Hall]

OK, I've got sformat, but I'm damned if I can figure out how to make it
change the sector size.

I've run through it twice, once with the -r option and once without.  I've
answered the appropriate questions about changing the geometry and the
desired sector size.  It grovels through the disk, says it's formatting, but
doesn't change the sector size as reported by prtvtoc ....

Is there a command line I can use that will let me just run it unattended?
All I want to do it reformat the disk and change the secttor size from 516
to 512.  Everything else can stay the same.  I don't care what the
partitions are, since I'm going to fx the disk anyway.

Thanks.

-Shel