Reduce diffs against fdisk/fdisk.8.

This commit is contained in:
Yoshihiro Takahashi 2007-05-09 11:46:31 +00:00
parent 856d5abeed
commit a39259958d
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=169419

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@ -27,31 +27,34 @@ The BIOS brings in sector 0 and verifies the magic number.
The sector
0 boot code then searches the partition table to determine which
partition is marked
.Em active .
.Dq active .
This boot code then brings in the bootstrap from the
.Em active
partition and, if marked bootable, runs it.
Under DOS,
you can have one or more partitions with one
.Em active .
The DOS
active partition and, if marked bootable, runs it.
Under
.Tn DOS ,
you can have one or more partitions with one active.
The
.Tn DOS
.Nm
utility can be used to divide space on the disk into partitions and set one
.Em active .
active.
.Sh DESCRIPTION
The
.Fx
.Nm
utility serves a similar purpose to the DOS program.
utility,
.Nm ,
serves a similar purpose to the
.Tn DOS
utility.
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
.Ar configfile ,
and is designed to be used by other scripts/programs.
.Pp
Options are:
.Bl -tag -width time
.Bl -tag -width indent
.It Fl a
Change the active partition only.
Ignored if
@ -59,17 +62,9 @@ Ignored if
is given.
.It Fl B
Reinitialize the boot code contained in sector 0 of the disk.
Ignored
if
Ignored if
.Fl f
is given.
.It Fl I
Initialize the partition table.
One
.Fx
slice covering the entire disk will be created.
Some space at the start of the disk will reserved for the IPL program
and the pc98 partition table itself.
.It Fl f Ar configfile
Set partition values using the file
.Ar configfile .
@ -78,14 +73,16 @@ The
always modifies existing partitions, unless
.Fl i
is also given, in which case all existing partitions are deleted (marked
as "unused") before the
as
.Dq unused )
before the
.Ar configfile
is read.
The
.Ar configfile
can be "-", in which case
.Ar stdin
is read.
can be
.Sq Fl ,
in which case standard input is read.
See
.Sx CONFIGURATION FILE ,
below, for file syntax.
@ -93,7 +90,7 @@ below, for file syntax.
.Em WARNING :
when
.Fl f
is used, you are not asked if you really want to write the partition
is used, you are not asked if you really want to write the partitions
table (as you are in the interactive mode).
Use with caution!
.It Fl i
@ -103,6 +100,13 @@ This implies
unless
.Fl f
is given.
.It Fl I
Initialize the partition table
for one
.Fx
slice covering the entire disk.
Some space at the start of the disk will reserved for the IPL program
and the pc98 partition table itself.
.It Fl s
Print summary information and exit.
.It Fl t
@ -113,7 +117,7 @@ option to see what would be written to the partition table.
Implies
.Fl v .
.It Fl u
Is used for updating (editing) sector 0 of the disk.
Update (edit) the disk's partition table.
Ignored if
.Fl f
is given.
@ -126,30 +130,26 @@ is used,
.Nm
prints out the partition table that is written to the disk.
.It Fl 12345678
Operate on a single fdisk entry only.
Operate on a single partition table entry only.
Ignored if
.Fl f
is given.
.El
.Pp
The final disk name can be provided as a
.Sq bare
.Dq bare
disk name only, e.g.\&
.Ql da0 ,
or as a fully qualified device node under
.Pa /dev .
If omitted, the disks
.Ql wd0 ,
.Ql da0 ,
and
.Ql od0
are being searched in that order, until one is
being found responding.
.Pa da0 ,
or as a full pathname.
If omitted,
.Nm
tries to figure out the default disk device name from the
mounted root device.
.Pp
When called with no arguments, it prints the sector 0 partition table.
When called with no arguments, it prints the partition table.
An example follows:
.Bd -literal
******* Working on device /dev/rda0 *******
******* Working on device /dev/da0 *******
parameters extracted from in-core disklabel are:
cylinders=33075 heads=8 sectors/track=32 (256 blks/cyl)
@ -203,153 +203,143 @@ An example follows:
.Pp
The disk is divided into three partitions that happen to fill the disk.
The second partition overlaps the end of the first.
(Used for debugging purposes)
.Bl -tag -width "cyl, sector and head"
.It Em "sysmid"
(Used for debugging purposes.)
.Bl -tag -width ".Em cyl , sector No and Em head"
.It Em sysmid
is used to label the partition.
.Fx
reserves the
magic number 148 decimal (94 in hex).
.It Em start No and Em size
.It Xo
.Em start
and
.Em size
.Xc
fields provide the start address
and size of a partition in sectors.
.\" !PC98 .It Em "flag 80"
.\" specifies that this is the active partition.
.It Em cyl , sector No and Em head
fields are used to specify the beginning address
and end address for the partition.
.It Xo
.Em cyl , sector
and
.Em head
.Xc
fields are used to specify the beginning and end addresses of the partition.
.It Em "system Name"
is the name of the partition.
.It Em Note :
these numbers are calculated using BIOS's understanding of the disk geometry
and saved in the bootblock.
.El
.Pp
The flags
.Fl i
or
.Fl u
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
utility will enter a conversational mode.
This mode is designed not to change any data unless you explicitly tell it to.
The
.Nm
utility selects defaults for its questions to guarantee the above behavior.
.Em Note :
these numbers are calculated using BIOS's understanding of the disk geometry
and saved in the bootblock.
.Pp
It displays each partition
and ask if you want to edit it.
If you say yes,
it will step through each field showing the old value
and asking for a new one.
When you are done with a partition,
The
.Fl i
and
.Fl u
flags are used to indicate that the partition data is to be updated.
Unless the
.Fl f
option is also given,
.Nm
will display it and ask if it is correct.
will enter a conversational mode.
In this mode, no changes will be written to disk unless you explicitly tell
.Nm
to.
.Pp
The
.Nm
utility will then proceed to the next entry.
utility will display each partition and ask whether you want to edit it.
If you say yes,
.Nm
will step through each field, show you the old value,
and ask you for a new one.
When you are done with the partition,
.Nm
will display it and ask you whether it is correct.
It will then proceed to the next entry.
.Pp
Getting the
.Em cyl , sector ,
and
.Em head
fields correct is tricky.
So by default,
fields correct is tricky, so by default,
they will be calculated for you;
you can specify them if you choose.
you can specify them if you choose to though.
.Pp
After all the partitions are processed,
you are given the option to change the
.Em active
.Dq active
partition.
Finally,
when the all the data for the first sector has been accumulated,
you are asked if you really want to rewrite sector 0.
Only if you answer yes,
will the data be written to disk.
Finally, when all the new data for sector 0 has been accumulated,
you are asked to confirm whether you really want to rewrite it.
.Pp
The difference between the
.Fl u
flag and
and
.Fl i
flag is that
flags is that
the
.Fl u
flag just edits the fields as they appear on the disk.
While the
flag edits (updates) the existing partition parameters
while the
.Fl i
flag is used to "initialize" sector 0;
flag is used to
.Dq initialize
them (old values will be ignored);
it will setup the last BIOS partition to use the whole disk for
.Fx ;
and make it active.
.Sh NOTES
The automatic calculation of starting cylinder etc.\& uses
a set of figures that represent what the BIOS thinks is the
geometry of the drive.
These figures are by default taken from the incore disklabel,
but the program initially gives you an opportunity to change them.
This allows the user to create a bootblock that can work with drives
a set of figures that represent what the BIOS thinks the
geometry of the drive is.
These figures are taken from the in-core disklabel by default,
but
.Nm
initially gives you an opportunity to change them.
This allows you to create a bootblock that can work with drives
that use geometry translation under the BIOS.
.Pp
If you hand craft your disk layout,
please make sure that the
.Fx
partition starts on a cylinder boundary.
A number of decisions made later may assume this.
(This might not be necessary later.)
.Pp
Editing an existing partition will most likely cause you to
lose all the data in that partition.
Editing an existing partition will most likely result in the loss of
all data in that partition.
.Pp
You should run this program interactively once or twice to see how it
works.
You should run
.Nm
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.
There are subtleties that
.Nm
detects that are not fully explained in this manual page.
.Sh CONFIGURATION FILE
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
The syntax of this file is very simple;
each line is either a comment or a specification, as follows:
.Bl -tag -width indent
.It Ic # Ar comment ...
Lines beginning with a
.Ic #
.Ar comment ...
.Xc
Lines beginning with a "#" are comments and are ignored.
.It Xo
.Ic g
.Ar spec1
.Ar spec2
.Ar spec3
.Xc
Set the BIOS geometry used in partition calculations.
are comments and are ignored.
.It Ic g Ar spec1 spec2 spec3
Set the BIOS geometry used in slice calculations.
There must be
three values specified, with a letter preceding each number:
.Bl -tag -width Ds
.Sm off
.It Cm c Ar num
.Sm on
.Bl -tag -width indent
.It Cm c Ns Ar num
Set the number of cylinders to
.Ar num .
.Sm off
.It Cm h Ar num
.Sm on
.It Cm h Ns Ar num
Set the number of heads to
.Ar num .
.Sm off
.It Cm s Ar num
.Sm on
.It Cm s Ns Ar num
Set the number of sectors/track to
.Ar num .
.El
@ -368,10 +358,12 @@ It is an error if the following is not true:
.Ed
.Pp
The number of cylinders should be less than or equal to 1024, but this
is not enforced, although a warning will be output.
is not enforced, although a warning will be printed.
Note that bootable
.Fx
partitions (the "/" file system) must lie completely within the
partitions (the
.Dq Pa /
file system) 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
@ -382,16 +374,10 @@ g c1019 h39 s63
g h39 c1019 s63
g s63 h39 c1019
.Ed
.It Xo
.Ic p
.Ar partition
.Ar type
.Ar start
.Ar length
.Xc
.It Ic p Ar partition type start length
Set the partition given by
.Ar partition
(1-4) to type
(1-8) to type
.Ar type ,
starting at sector
.Ar start
@ -400,14 +386,20 @@ for
sectors.
.Pp
Only those partitions explicitly mentioned by these lines are modified;
any partition not referenced by a "p" line will not be modified.
any partition not referenced by a
.Ic 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
(marked as unused), and these
.Ic 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.
set, multiple
.Ic p
lines must be specified; one for each partition.
.Pp
These partition lines must occur after any geometry specification lines,
if one is present.
@ -419,7 +411,9 @@ is 165 for
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
dummy values (such as
.Dq 0 )
must still be specified for
.Ar start
and
.Ar length .
@ -429,22 +423,17 @@ necessary, and the end offset will be rounded downwards to a cylinder
boundary if necessary.
.Pp
Example: to clear partition 4 and mark it as unused:
.Bd -literal -offset indent
p 4 0 0 0
.Ed
.Pp
.Dl "p 4 0 0 0"
.Pp
Example: to set partition 1 to a
.Fx
partition, starting at sector 1
for 2503871 sectors (note: these numbers will be rounded upwards and
downwards to correspond to head and cylinder boundaries):
.Bd -literal -offset indent
p 1 165 1 2503871
.Ed
.It Xo
.Ic a
.Ar partition
.Xc
.Pp
.Dl "p 1 165 1 2503871"
.It Ic a Ar partition
Make
.Ar partition
the active partition.
@ -452,9 +441,8 @@ Can occur anywhere in the config file, but only
one must be present.
.Pp
Example: to make partition 1 the active partition:
.Bd -literal -offset indent
a 1
.Ed
.Pp
.Dl "a 1"
.El
.Sh SEE ALSO
.Xr boot98cfg 8 ,
@ -462,15 +450,11 @@ a 1
.Xr newfs 8
.Sh BUGS
The default boot code will not necessarily handle all partition types
correctly, in particular those introduced since MS-DOS 6.x.
correctly, in particular those introduced since
.Tn MS-DOS
6.x.
.Pp
The entire program should be made more user-friendly.
.Pp
Throughout this man page, the term
.Sq partition
is used where it should actually be
.Sq slice ,
in order to conform with the terms used elsewhere.
The entire utility should be made more user-friendly.
.Pp
You cannot use this command to completely dedicate a disk to
.Fx .