DISKPART(8) — Unix Programmer’s Manual
NAME
diskpart − calculate default disk partition sizes
SYNOPSIS
/etc/diskpart [ options ] disk-type
DESCRIPTION
Diskpart is used to calculate the disk partition sizes based on the default rules used at Berkeley. 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 sufficient 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”.
Partition20-60 MB61-205 MB206-355 MB356+ MB
a15884158841588415884
b10032334403344066880
d15884158841588415884
eunused5593655936307200
hunusedunused291346291346
If an unknown disk type is specified, diskpart will prompt for the required disk geometry information.
OPTIONS
−p Produces tables suitable for inclusion in a device driver.
−d Generates an entry suitable for inclusion in the disk description file /etc/disktab; c.f. disktab(5).
SEE ALSO
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