

DISKPART(8)	    UNIX Programmer's Manual	      DISKPART(8)


NAME
     diskpart - calculate default disk partition sizes

SYNOPSIS
     /usr/sbin/diskpart [ -p ] [ -d ] disk-type

DESCRIPTION
     _D_i_s_k_p_a_r_t 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 suit-
     able for inclusion in the disk description file /_e_t_c/_d_i_s_k_t_a_b
     is generated; c.f.  _d_i_s_k_t_a_b(5).  On disks that use _b_a_d_1_4_4-
     style bad-sector forwarding, space is left in the last par-
     tition on the disk for a bad sector forwarding table.  The
     space reserved is one track for the replicated copies of the
     table and sufficient tracks to hold a pool of 126 sectors to
     which bad sectors are mapped.  For more information, see
     _b_a_d_1_4_4(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' parti-
     tion 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' parti-
     tion 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
     _d_i_s_k_p_a_r_t 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, _d_i_s_k_p_a_r_t 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


Printed 11/26/99	November 17, 1996			1


DISKPART(8)	    UNIX Programmer's Manual	      DISKPART(8)


     layouts.

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


Printed 11/26/99	November 17, 1996			2