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Diffstat (limited to 'sbin/fdisk/fdisk.8')
| -rw-r--r-- | sbin/fdisk/fdisk.8 | 272 |
1 files changed, 238 insertions, 34 deletions
diff --git a/sbin/fdisk/fdisk.8 b/sbin/fdisk/fdisk.8 index 36780e7..a43a85a 100644 --- a/sbin/fdisk/fdisk.8 +++ b/sbin/fdisk/fdisk.8 @@ -1,4 +1,4 @@ -.Dd April 4, 1993 +.Dd October 4, 1996 .Dt FDISK 8 .\".Os BSD 4 .Sh NAME @@ -10,32 +10,14 @@ .Op Fl u .Op Fl a .Op Fl 0123 -.Op disk +.Op Ar disk .Bl -tag -width time -.It Fl u -Is used for updating (editing) sector 0 of the disk. -.It Fl i -Initializes sector 0 of the disk. This implies -.Fl u . -.It Fl a -Change the active partition only. -.It Fl 0123 -Operate on a single fdisk entry only. -.El -.Pp -The final disk name can be provided as a -.Sq bare -disk name only, e.g. -.Ql sd0 , -or as a fully qualified device node under -.Pa /dev . -If omitted, the disks -.Ql wd0 , -.Ql sd0 , -and -.Ql od0 -are being searched in that order, until one is -being found responding. +.Nm fdisk +.Op Fl f Ar configfile +.Op Fl i +.Op Fl v +.Op Fl t +.Op Ar disk .Sh PROLOGUE In order for the BIOS to boot the kernel, certain conventions must be adhered to. @@ -60,9 +42,84 @@ The DOS program can be used to divide space on the disk into partitions and set one .Em active. .Sh DESCRIPTION +.Pp The FreeBSD program .Nm -serves a similar purpose to the DOS program. +serves a similar purpose to the DOS program. The first form is used to +display partition information or to interactively edit the partition +table. The second is used to write a partition table using a +.Ar configfile +and is designed to be used by other scripts/programs. +.Pp +Options are: +.It Fl u +Is used for updating (editing) sector 0 of the disk. Ignored if +.Fl f +is given. +.It Fl i +Initializes sector 0 of the disk. This implies +.Fl u , +unless +.Fl f +is given. +.It Fl a +Change the active partition only. Ignored if +.Fl f +is given. +.It Fl 0123 +Operate on a single fdisk entry only. Ignored if +.Fl f +is given. +.It Fl f Ar configfile +Set partition values using the file +.Ar configfile . +The +.Ar configfile +always modifies existing partitions, unless +.Fl i +is also given, in which case all existing partitions are deleted (marked +as "unused") before the +.Ar configfile +is read. The +.Ar configfile +can be "-", in which case +.Ar stdin +is read. See +.Em CONFIGURATION FILE , +below, for file syntax. +.Pp +.Em WARNING: +when +.Fl f +is used, you are not asked if you really want to write the partition +table (as you are in the interactive mode). Use with caution! +.It Fl t +Test mode; do not write partition values. Generally used with the +.Fl f +option to see what would be written to the partition table. Implies +.Fl v . +.It Fl v +Be verbose. When +.Fl f +is used, +.Nm +prints out the partition table that is written to the disk. +.El +.Pp +The final disk name can be provided as a +.Sq bare +disk name only, e.g. +.Ql sd0 , +or as a fully qualified device node under +.Pa /dev . +If omitted, the disks +.Ql wd0 , +.Ql sd0 , +and +.Ql od0 +are being searched in that order, until one is +being found responding. +.Pp When called with no arguments, it prints the sector 0 partition table. An example follows: @@ -119,8 +176,11 @@ The flags .Fl i or .Fl u -are used to indicate that the partition data is to be updated. -The +are used to indicate that the partition data is to be updated, unless the +.Fl f +option is used. If the +.Fl f +option is not used, the .Nm program will enter a conversational mode. This mode is designed not to change any data unless you explicitly tell it to. @@ -188,11 +248,151 @@ A number of decisions made later may assume this. Editing an existing partition will most likely cause you to lose all the data in that partition. .Pp -You should run this program interactively once or twice to see how it works. -This is completely safe as long as you answer the last question in the negative. -There are subtleties -that the program detects -that are not fully explained in this manual page. +You should run this program interactively once or twice to see how it +works. This is completely safe as long as you answer the last question +in the negative. There are subtleties that the program detects that are +not fully explained in this manual page. +.Sh CONFIGURATION FILE +.Pp +When the +.Fl f +option is given, a disk's partition table can be written using values +from a +.Ar configfile . +The syntax of this file is very simple. Each line is either a comment or +a specification, and whitespace (except for newlines) are ignored: +.Bl -tag -width Ds +.It Xo +.Ic # +.No Ar comment ... +.Xc +Lines beginning with a "#" are comments and are ignored. +.It Xo +.Ic g +.No Ar spec1 +.No Ar spec2 +.No Ar spec3 +.Xc +Set the BIOS geometry used in partition calculations. There must be +three values specfied, with a letter preceding each number: +.Bl -tag -width Ds +.Sm off +.It Cm c No Ar num +.Sm on +Set the number of cylinders to +.Ar num . +.Sm off +.It Cm h No Ar num +.Sm on +Set the number of heads to +.Ar num . +.Sm off +.It Cm s No Ar num +.Sm on +Set the number of sectors/track to +.Ar num . +.El +.Pp +These specs can occur in any order, as the leading letter determines +which value is which; however, all three must be specified. +.Pp +This line must occur before any lines that specify partition +information. +.Pp +It is an error if the following is not true: +.Pp +.nf + 1 <= number of cylinders + 1 <= number of heads <= 256 + 1 <= number of sectors/track < 64 +.fi +.Pp +The number of cylinders should be less than or equal to 1024, but this +is not enforced, although a warning will be output. Note that bootable +FreeBSD partitions (the "/" filesystem) must lie completely within the +first 1024 cylinders; if this is not true, booting may fail. +Non-bootable partitions do not have this restriction. +.Pp +Example (all of these are equivalent), for a disk with 1019 cylinders, +39 heads, and 63 sectors: +.Pp +.nf + g c1019 h39 s63 + g h39 c1019 s63 + g s63 h39 c1019 +.fi +.It Xo +.Ic p +.No Ar partition +.No Ar type +.No Ar start +.No Ar length +.Xc +Set the partition given by +.Ar partition +(0-3) to type +.Ar type , +starting at sector +.Ar start +for +.Ar length +sectors. +.Pp +Only those partitions explicitly mentioned by these lines are modified; +any partition not referenced by a "p" line will not be modified. +However, if an invalid partition table is present, or the +.Fl i +option is specified, all existing partition entries will be cleared +(marked as unused), and these "p" lines will have to be used to +explicitly set partition information. If multiple partitions need to be +set, multiple "p" lines must be specified; one for each partition. +.Pp +These partition lines must occur after any geometry specification lines, +if one is present. +.Pp +The +.Ar type +is 165 for FreeBSD partitions. Specifying a partition type of zero is +the same as clearing the partition and marking it as unused; however, +dummy values (such as "0") must still be specified for +.Ar start +and +.Ar length . +.Pp +Note: the start offset will be rounded upwards to a head boundary if +necessary, and the end offset will be rounded downwards to a cylinder +boundary if necessary. +.Pp +Example: to clear partition 3 and mark it as unused: +.Pp +.nf + p 3 0 0 0 +.fi +.Pp +Example: to set partition 0 to a FreeBSD partition, starting at sector 1 +for 2503871 sectors (note: these numbers will be rounded upwards and +downwards to correspond to head and cylinder boundaries): +.Pp +.nf + p 0 165 1 2503871 +.fi +.It Xo +.Ic a +.No Ar partition +.Xc +Make +.Ar partition +the active partition. Can occur anywhere in the config file, but only +one must be present. +.Pp +Example: to make partition 0 the active partition: +.Pp +.nf + a 0 +.fi + +.El +.Pp .Sh SEE ALSO .Xr disklabel 8 .Sh BUGS @@ -203,3 +403,7 @@ Throughout this man page, the term is used where it should actually be .Sq slice , in order to conform with the terms used elsewhere. +.Pp +You cannot use this command to completely dedicate a disk to FreeBSD. The +.Xr disklabel 8 +command must be used for this. |
