diskpart(8) — Unsupported
Name
diskpart − calculate default disk partition sizes
Syntax
/etc/diskpart [ −p ] [ −d ] disk-type
Description
The diskpart command 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. For further information, see disktab(5). Space is always 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(.).
The disk partition sizes are based on the total amount of space on the disk as give 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, including the space reserved for the bad sector forwarding table. 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 prompts for the required disk geometry information.
Restrictions
Certain default partition sizes are based on historical artifacts (for example, RP06), and may result in unsatisfactory layouts.
When using the −d flag, alternate disk names are not included in the output.
The diskpart command does not understand how to handle drives attached to the controllers described on the ra() reference page (MSCP disk interface).