Re: Possibility of increasing default MAXPARTITIONS from 8 to 16

[Matthew Dillon]

::   It seems reasonable to me, although there may be issues with finding a bit
::in the minor number - I think they've pretty much all been taken.
::
::-DG
::
::David Greenman
:
:    Cripes!  Now that is really annoying.  da0a is 4,0 and da1a is 4,8.
:
:                                       -Matt

    minor device number:

    t = type

    u = unit  (upper bits split off from lower)

    s = slice (assuming only 8 slices)
                0       noslice
                1       whole disk
                2-5     s1,s2,s3,s4
                6-8     unused

    p = partition

    - = cannot be used


        tttttttu uuusssss -------- uuuuuppp             minor layout for disks
        11111111 11111111 -------- 11111111             mask for uminor

    Our only hope as far as I can tell is to take the upper two bits of the
    slice (bits 19 and 20) and use them for the partition instead.

    As far as I can tell, only slices 0-5 are used, requiring only 3 bits.

    Can someone check my work?  Are bits 19 and 20 unused by any disk 
    devices?

                                        -Matt
                                        Matthew Dillon 
                                        <[EMAIL PROTECTED]>


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