1.\" Copyright (c) 1983, 1991 Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)diskpart.8 6.6 (Berkeley) 3/16/91 33.\" 34.Dd March 16, 1991 35.Dt DISKPART 8 36.Os BSD 4 37.Sh NAME 38.Nm diskpart 39.Nd calculate default disk partition sizes 40.Sh SYNOPSIS 41.Nm diskpart 42.Op Fl p 43.Op Fl d 44.Op Fl s Ar size 45.Ar disk-type 46.Sh DESCRIPTION 47.Nm Diskpart 48is used to calculate the disk partition sizes based on the 49default rules used at Berkeley. 50.Pp 51Available options and operands: 52.Bl -tag -width Fl 53.It Fl p 54Tables suitable for inclusion in a device driver 55are produced. 56.It Fl d 57An entry suitable for inclusion in the disk 58description file 59.Pa /etc/disktab 60is generated; for example, 61.Xr disktab 5 . 62.It Fl s Ar size 63The size of the disk may be limited to 64.Ar size 65with the 66.Fl s 67option. 68.El 69.Pp 70On disks that use 71.Xr bad144 8 72type of 73bad-sector forwarding, 74space is normally left in the last partition on the disk 75for a bad sector forwarding table, although this space 76is not reflected in the tables produced. The space reserved 77is one track for the replicated copies of the table and 78sufficient tracks to hold a pool of 126 sectors to which bad sectors 79are mapped. For more information, see 80.Xr bad144 8 . 81The 82.Fl s 83option is intended for other controllers which reserve some space at the end 84of the disk for bad-sector replacements or other control areas, 85even if not a multiple of cylinders. 86.Pp 87The disk partition sizes are based on the total amount of 88space on the disk as given in the table below (all values 89are supplied in units of sectors). The 90.Ql c 91partition 92is, by convention, used to access the entire physical disk. 93The device driver tables include 94the space reserved for the bad sector forwarding table in the 95.Ql c 96partition; 97those used in the disktab and default formats exclude reserved tracks. 98In normal operation, either the 99.Ql g 100partition is used, or the 101.Ql d , 102.Ql e , 103and 104.Ql f 105partitions are used. The 106.Ql g 107and 108.Ql f 109partitions 110are variable-sized, occupying whatever space remains after allocation 111of the fixed sized partitions. 112If the disk is smaller than 20 Megabytes, then 113.Nm diskpart 114aborts with the message 115.Dq Li disk too small, calculate by hand . 116.Bl -column Partition 20-60\ MB 61-205\ MB 206-355\ MB 356+\ MB 117Partition 20-60 MB 61-205 MB 206-355 MB 356+ MB 118a 15884 15884 15884 15884 119b 10032 33440 33440 66880 120d 15884 15884 15884 15884 121e unused 55936 55936 307200 122h unused unused 291346 291346 123.El 124.Pp 125If an unknown disk type is specified, 126.Nm diskpart 127will prompt for the required disk geometry information. 128.Sh SEE ALSO 129.Xr disktab 5 , 130.Xr bad144 8 131.Sh BUGS 132Most default partition sizes are based on historical artifacts 133(like the RP06), and may result in unsatisfactory layouts. 134.Pp 135When using the 136.Fl d 137flag, alternate disk names are not included 138in the output. 139.Sh HISTORY 140The 141.Nm 142command appeared in 143.Bx 4.2 . 144