optimal mkfs m,n for Rm80 and Eagle on Vax 750 4.1 BSD

[wls at astrovax.UUCP]

>  You should remind your wizard that the cookbook value 217 for
>  the RM80 is wrong.  7 Surfaces * 31 sectors / 2 sectors per block is
>  108.5 which can easily be issued as 107 or 108 and move
>  the disk heads every 15 or so blocks rather than every 7 blocks.

>  Yours in nitpicking system performance,
>  wdc

Nitpicking yes, but also wrong.  The correct number is 217 =
7 surfaces * 2 heads per surface (!) *  31 sectors / 2 sectors per block

There are 434 sectors/cylinder.  I have done enough reallocating partitions
on an Rm80 lately after various new bad blocks mysteriously appeared to know
these numbers in my bones.
-- 
Bill Sebok	Princeton Univ. Astrophysics
{allegra,akgua,burl,cbosgd,decvax,ihnp4,kpno,princeton}!astrovax!wls