4.3BSD - /usr/man/cat8/diskpart.0

DISKPART(8)                                                        DISKPART(8)


NAME
       diskpart - calculate default disk partition sizes

SYNOPSIS
       /etc/diskpart [ -p ] [ -d ] disk-type

DESCRIPTION
       Diskpart  is  used  to  calculate the disk partition sizes based on the
       default rules used at Berkeley.  If the -p option is  supplied,  tables
       suitable  for  inclusion  in  a  device driver are produced.  If the -d
       option is supplied,  an  entry  suitable  for  inclusion  in  the  disk
       description file /etc/disktab is generated; c.f.  disktab(5).  On disks
       that use bad144-style bad-sector forwarding, space is left in the  last
       partition  on  the  disk  for a bad sector forwarding table.  The space
       reserved is one track for the replicated copies of the table and suffi‐
       cient  tracks  to  hold  a pool of 126 sectors to which bad sectors are
       mapped.  For more information, see bad144(8).

       The disk partition sizes are based on the total amount of space on  the
       disk  as  given in the table below (all values are supplied in units of
       512 byte sectors).  The ‘c’ partition is, by convention, used to access
       the  entire  physical disk.  The device driver tables include the space
       reserved for the bad sector forwarding  table  in  the  ‘c’  partition;
       those  used in the disktab and default formats exclude reserved tracks.
       In normal operation, either the ‘g’ partition is used, or the ‘d’, ‘e’,
       and  ‘f’ partitions are used.  The ‘g’ and ‘f’ partitions are variable-
       sized, occupying whatever space remains after allocation of  the  fixed
       sized  partitions.   If  the  disk  is  smaller than 20 Megabytes, then
       diskpart aborts with the message ‘‘disk too small, calculate by hand’’.

            Partition  20-60 MB  61-205 MB  206-355 MB  356+ MB
            a          15884     15884      15884       15884
            b          10032     33440      33440       66880
            d          15884     15884      15884       15884
            e          unused    55936      55936       307200
            h          unused    unused     291346      291346


       If  an  unknown  disk  type  is specified, diskpart will prompt for the
       required disk geometry information.

SEE ALSO
       disktab(5), bad144(8)

BUGS
       Certain default partition sizes are based on historical artifacts (e.g.
       RP06), and may result in unsatisfactory layouts.

       When  using  the  -d flag, alternate disk names are not included in the
       output.


4th Berkeley Distribution        May 30, 1986                      DISKPART(8)