Cylinder boundaries in 4.3BSD

[Michael I. Bushnell]

In article <8808 at eddie.MIT.EDU> nessus at athena.mit.edu (Doug Alan) writes:

[He wants to stick a non-DEC drive on a Microvax-II.]

What we do is make the disk look like an RA-81 or an RD-51. (We have
two different partition tables for the two different kinds.)  If you
have to get "standard" kernels to run on it, then I would suggest
making it look like an RA-81>.  You will need to fix up your own
/etc/disktab entry, but the kernel reads the disk size at boot time,
and all the other partitions will be the same.  This gives the
following picture:




    [aaaaaaaa][bbbbbbbbbbb][hhhhhhhhh][ddddddd][eeeeeeee][ffffffff]
                                      [ggggggggggggggggggggggggggg]
    [ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc]

The f, g, and c sizes are determined at boot time.

If you make it look like an RD53, then you will still need the special
disktab entry, but you won't have the benifit of separate h and g
partitions.

Yet another possibility, if you don't really care about getting
"standard" kernels to run on them, is to make it look like an rd51.
rd51 is the type the controller returns if it can't determine the
type.  That is what we do for almost all our large microvax disks.

Hope this helps.

                N u m q u a m   G l o r i a   D e o 

			Michael I. Bushnell
			HASA - "A" division
14308 Skyline Rd NE				Computer Science Dept.
Albuquerque, NM  87123		OR		Farris Engineering Ctr.
	OR					University of New Mexico
mike at turing.unm.edu				Albuquerque, NM  87131
{ucbvax,gatech}!unmvax!turing.unm.edu!mike