diff options
Diffstat (limited to 'sbin/disklabel/disklabel.8')
-rw-r--r-- | sbin/disklabel/disklabel.8 | 725 |
1 files changed, 398 insertions, 327 deletions
diff --git a/sbin/disklabel/disklabel.8 b/sbin/disklabel/disklabel.8 index 9945038..6a57d40 100644 --- a/sbin/disklabel/disklabel.8 +++ b/sbin/disklabel/disklabel.8 @@ -35,7 +35,7 @@ .\" @(#)disklabel.8 8.2 (Berkeley) 4/19/94 .\" $FreeBSD$ .\" -.Dd July 30, 1999 +.Dd March 15, 2003 .Dt DISKLABEL 8 .Os .Sh NAME @@ -47,96 +47,91 @@ .Ar disk .Nm .Fl w -.Op Fl r -.Op Fl n +.Op Fl nr .Ar disk disktype Ns | Ns Cm auto -.Oo Ar packid Oc +.Op Ar packid .Nm .Fl e -.Op Fl r -.Op Fl n +.Op Fl nr .Ar disk .Nm .Fl R -.Op Fl r -.Op Fl n -.Ar disk Ar protofile +.Op Fl nr +.Ar disk protofile .Pp .Nm .Fl B -.Oo -.Fl b Ar boot -.Oc +.Op Fl b Ar boot .Ar disk -.Op Ar disktype Ns | Ns Cm auto .Nm -.Fl w -.Fl B +.Fl w B .Op Fl n -.Oo -.Fl b Ar boot -.Oc +.Op Fl b Ar boot .Ar disk disktype Ns | Ns Cm auto -.Oo Ar packid Oc +.Op Ar packid .Nm -.Fl R -.Fl B +.Fl R B .Op Fl n -.Oo -.Fl b Ar boot -.Oc -.Ar disk Ar protofile +.Op Fl b Ar boot +.Ar disk protofile .Sh DESCRIPTION The .Nm utility -installs, examines or modifies the label on a disk drive or pack. When writing +installs, examines or modifies the label on a disk drive or pack. +When writing the label, it can be used to change the drive identification, the disk -partitions on the drive, or to replace a damaged label. There are several forms -of the command that read (display), install or edit the label on a disk. In -addition, +partitions on the drive, or to replace a damaged label. +There are several forms +of the command that read (display), install, or edit the label on a disk. +In addition, .Nm can install bootstrap code. -.Ss Raw or in-core label -.Pp +.Ss Raw or In-Core Label The disk label resides close to or at the beginning of each disk slice. -For faster access, the kernel maintains a copy in core at all times. By -default, most +For faster access, the kernel maintains a copy in core at all times. +By default, most .Nm -access the in-core copy of the label. To access the raw (on-disk) copy, use the +access the in-core copy of the label. +To access the raw (on-disk) copy, use the .Fl r -option. This option allows a label to be installed on a disk without kernel +option. +This option allows a label to be installed on a disk without kernel support for a label, such as when labels are first installed on a system; it -must be used when first installing a label on a disk. The specific effect of +must be used when first installing a label on a disk. +The specific effect of .Fl r is described under each command. -.Pp -.Ss Disk device name -.Pp +.Ss Disk Device Name All .Nm forms require a disk device name, which should always be the raw -device name representing the disk or slice. For example +device name representing the disk or slice. +For example, .Pa da0 -represents the entire disk regardless of any DOS partitioning, +represents the entire disk regardless of any +.Tn DOS +partitioning, and .Pa da0s1 -represents a slice. Some devices, most notably -.Ar ccd , +represents a slice. +Some devices, most notably +.Xr ccd 4 , require that the .Dq whole-disk (or -.Dq c ) -partition be specified. For example +.Ql c ) +partition be specified. +For example, .Pa ccd0c . -You do not have to include the +When specifying the device, +the .Pa /dev/ -path prefix when specifying the device. -The +path prefix may be omitted; +the .Nm utility will automatically prepend it. -.Ss Reading the disk label -.Pp +.Ss Reading the Disk Label To examine the label on a disk drive, use .Nm without options: @@ -151,68 +146,68 @@ represents the raw disk in question, and may be in the form or .Pa /dev/da0c . It will display all of the parameters associated with the drive and its -partition layout. Unless the +partition layout. +Unless the .Fl r -flag is given, +option is given, the kernel's in-core copy of the label is displayed; if the disk has no label, or the partition types on the disk are incorrect, the kernel may have constructed or modified the label. If the .Fl r -flag is given, +option is given, .Nm -reads the label from the raw disk and displays it. Both versions are usually +reads the label from the raw disk and displays it. +Both versions are usually identical except in the case where a label has not yet been initialized or is corrupt. -.Ss Writing a standard label -.Pp +.Ss Writing a Standard Label To write a standard label, use the form .Pp .Nm .Fl w -.Op Fl r -.Op Fl n +.Op Fl nr .Ar disk disktype Ns | Ns Cm auto -.Oo Ar packid Oc -.Pp -.Nm -.Fl w -.Op Fl r -.Op Fl n -.Ar disk -.Cm auto +.Op Ar packid .Pp The required arguments to .Nm -are the drive to be labeled and the drive type as described in the +are the drive to be labeled, and the drive type as described in the +.Xr disktab 5 +file. +The drive parameters and partitions are taken from that file. +If different disks of the same physical type are to have different partitions, +it will be necessary to have separate .Xr disktab 5 -file. The drive parameters and partitions are taken from that file. If -different disks of the same physical type are to have different partitions, it -will be necessary to have separate disktab entries describing each, or to edit -the label after installation as described below. The optional argument is a -pack identification string, up to 16 characters long. The pack id must be -quoted if it contains blanks. +entries describing each, or to edit +the label after installation as described below. +The optional argument is a +pack identification string, up to 16 characters long. +The +.Ar packid +must be quoted if it contains blanks. .Pp -If the +If .Fl n -flag is given, no data will be written to the device, and instead the -disklabel that would have been written will be printed to stdout. +is used, no data will be written to the device, and instead the +disk label that would have been written will be printed to standard output. .Pp If the .Fl r -flag is given, the disk sectors containing the label and bootstrap +option is given, the disk sectors containing the label and bootstrap will be written directly. A side-effect of this is that any existing bootstrap code will be overwritten -and the disk rendered unbootable. See the boot options below for a method of +and the disk rendered unbootable. +See the boot options below for a method of writing the label and the bootstrap at the same time. If .Fl r is not specified, -the existing label will be updated via the in-core copy and any bootstrap +the existing label will be updated via the in-core copy, and any bootstrap code will be unaffected. If the disk does not already have a label, the .Fl r -flag must be used. +option must be used. In either case, the kernel's in-core label is replaced. .Pp For a virgin disk that is not known to @@ -221,13 +216,22 @@ For a virgin disk that is not known to can be specified as .Cm auto . In this case, the driver is requested to produce a virgin label for the -disk. This might or might not be successful, depending on whether the +disk. +This might or might not be successful, depending on whether the driver for the disk is able to get the required data without reading -anything from the disk at all. It will likely succeed for all SCSI -disks, most IDE disks, and vnode devices. Writing a label to the +anything from the disk at all. +It will likely succeed for all +.Tn SCSI +disks, most +.Tn IDE +disks, and +.Cm vnode +type memory disks +.Pq Xr md 4 . +Writing a label to the disk is the only supported operation, and the .Ar disk -itself must be provided as the canonical name, i.e. not as a full +itself must be provided as the canonical name, i.e., not as a full path name. .Pp For most harddisks, a label based on percentages for most partitions (and @@ -235,167 +239,176 @@ one partition with a size of .Ql * ) will produce a reasonable configuration. .Pp -PC-based systems have special requirements in order for the BIOS to properly -recognize a +PC-based systems have special requirements in order for the +.Tn BIOS +to properly recognize a .Fx -disklabel. Older systems may require what is known as a -.Dq dangerously dedicated -disklabel, which creates a fake DOS partition to work around problems older -BIOSes have with modern disk geometries. -On newer systems you generally want -to create a normal DOS partition using -.Ar fdisk -and then create a +disk label. +Older systems may require what is known as a +.Dq dangerously-dedicated +disk label, which creates a fake +.Tn DOS +partition to work around problems older +.Tn BIOS Ns es +have with modern disk geometries. +On newer systems, a normal +.Tn DOS +partition should generally be created using +.Xr fdisk 8 , +and then a .Fx -disklabel within that slice. This is described -later on in this page. +disk label within that slice. +This is described later on in this page. .Pp -Installing a new disklabel does not in of itself allow your system to boot -a kernel using that label. You must also install boot blocks, which is +Installing a new disk label does not in of itself allow the system to boot +a kernel using that label. +Boot blocks must also be installed, which is described later on in this manual page. -.Ss Editing an existing disk label -.Pp +.Ss Editing an Existing Disk Label To edit an existing disk label, use the form .Pp .Nm .Fl e -.Op Fl r -.Op Fl n +.Op Fl nr .Ar disk .Pp This command reads the label from the in-core kernel copy, or directly from the disk if the .Fl r -flag is also specified. The label is written to a file in ASCII and then -supplied to an editor for changes. If no editor is specified in an +option is also specified. +The label is written to a file in +.Tn ASCII +format, and then supplied to an editor for changes. +If no editor is specified in the .Ev EDITOR environment variable, .Xr vi 1 -is used. When the editor terminates, the label file is used to rewrite the disk -label. Existing bootstrap code is unchanged regardless of whether +is used. +When the editor terminates, the label file is used to rewrite the disk label. +Existing bootstrap code is unchanged regardless of whether .Fl r -was specified. If +was specified. +If .Fl n -is specified, no data will be written to the device, and instead the -disklabel that would have been written will be printed to stdout. This is +is used, no data will be written to the device, and instead the +disk label that would have been written will be printed to standard output. +This is useful to see how a partitioning scheme will work out for a specific disk. -.Ss Restoring a disk label from a file -.Pp +.Ss Restoring a Disk Label From a File To restore a disk label from a file, use the form .Pp .Nm .Fl R -.Op Fl r -.Op Fl n -.Ar disk Ar protofile +.Op Fl nr +.Ar disk protofile .Pp .Nm -is capable of restoring a disk label that was previously saved in a file in ASCII format. +is capable of restoring a disk label that was previously saved in a file in +.Tn ASCII +format. The prototype file used to create the label should be in the same format as that -produced when reading or editing a label. Comments are delimited by -.Ar \&# -and newline. As when writing a new label, any existing bootstrap code will be +produced when reading or editing a label. +Comments are delimited by +.Ql # +and newline. +As when writing a new label, any existing bootstrap code will be clobbered if .Fl r -is specified and will be unaffected otherwise. See the boot options below for a +is specified, and will be unaffected otherwise. +See the boot options below for a method of restoring the label and writing the bootstrap at the same time. If .Fl n is used, no data will be written to the device, and instead the -disklabel that would have been written will be printed to stdout. This is +disk label that would have been written will be printed to standard output. +This is useful to see how a partitioning scheme will work out for a specific disk. -.Ss Installing bootstraps -.Pp +.Ss Installing Bootstraps The final three forms of .Nm -are used to install bootstrap code. If you are creating a +are used to install bootstrap code. +If a .Dq dangerously-dedicated -slice for compatibility with older PC systems, -you generally want to specify the raw disk name such as -.Pa da0 . -If you are creating a label within an existing DOS slice, -you should specify -the partition name such as -.Pa da0s1a . -Making a slice bootable can be tricky. If you are using a normal DOS -slice you typically install (or leave) a standard MBR on the base disk and -then install the -.Fx -bootblocks in the slice. +disk is created for compatibility with older PC systems, +the raw disk name such as +.Pa da0 +should be specified. +If an existing slice should be labeled, +the slice name such as +.Pa da0s1 +should be specified, +and to make it bootable, +.Tn MBR +on the base disk should probably be updated; see +.Xr fdisk 8 . .Pp .Nm .Fl B -.Oo -.Fl b Ar boot -.Oc +.Op Fl b Ar boot .Ar disk -.Oo Ar disktype Oc .Pp -This form installs the bootstrap only. It does not change the disk label. -You should never use this command on a base disk unless you intend to create a +This form installs the bootstrap only. +It does not change the disk label. +Never use this command on a base disk, such as +.Pa da0 , +unless the intent is to create a .Dq dangerously-dedicated -disk, such as -.Ar da0 . +disk. This command is typically run on a slice such as -.Ar da0s1 . +.Pa da0s1 . .Pp .Nm -.Fl w -.Fl B +.Fl w B .Op Fl n -.Oo -.Fl b Ar boot -.Oc -.Ar disk Ar disktype -.Oo Ar packid Oc +.Op Fl b Ar boot +.Ar disk disktype Ns | Ns Cm auto +.Op Ar packid .Pp This form corresponds to the -.Dq write label +.Dq "write label" command described above. In addition to writing a new volume label, it also installs the bootstrap. -If run on a base disk this command will create a +If run on a base disk, this command will create a .Dq dangerously-dedicated -label. This command is normally run on a slice rather than a base disk. +label. +This command is normally run on a slice rather than a base disk. If .Fl n is used, no data will be written to the device, and instead the -disklabel that would have been written will be printed to stdout. +disk label that would have been written will be printed to standard output. .Pp .Nm -.Fl R -.Fl B +.Fl R B .Op Fl n -.Oo -.Fl b Ar boot -.Oc -.Ar disk Ar protofile +.Op Fl b Ar boot +.Ar disk protofile .Pp This form corresponds to the -.Dq restore label +.Dq "restore label" command described above. In addition to restoring the volume label, it also installs the bootstrap. -If run on a base disk this command will create a +If run on a base disk, this command will create a .Dq dangerously-dedicated -label. This command is normally run on a slice rather than a base disk. +label. +This command is normally run on a slice rather than a base disk. .Pp The bootstrap commands always access the disk directly, so it is not necessary to specify the .Fl r -flag. If +option. +If .Fl n is used, no data will be written to the device, and instead the -disklabel that would have been written will be printed to stdout. +disk label that would have been written will be printed to standard output. .Pp -The bootstrap code is comprised of two boot programs, both -compiled into a single +The bootstrap code is comprised of two boot programs compiled into a single .Pa /boot/boot image. An alternative boot image may be specified with the .Fl b option. -.Ss Initializing/Formatting a bootable disk from scratch -.Pp -To initialize a disk from scratch the following sequence is recommended. +.Ss Initializing/Formatting a Bootable Disk From Scratch +To initialize a disk from scratch, the following sequence is recommended. Please note that this will wipe everything that was previously on the disk, including any .No non- Ns Fx @@ -405,51 +418,59 @@ slices. Use .Xr fdisk 8 to initialize the hard disk, and create a slice table, referred to -as the partition table in DOS. -Here you will define disk slices for your system. +as the +.Dq "partition table" +in +Tn DOS . .It Use .Nm -to define and write partitions and mount points. -You are not required to define the mount points here though, -they can be defined later using -.Xr mount 8 . +to define partitions on +.Fx +slices created in the previous step. .It Finally use .Xr newfs 8 -to create a file system on the new partition. +to create file systems on new partitions. +.El +.Pp A typical partitioning scheme would be to have an -.Dq a +.Ql a partition of approximately 128MB to hold the root file system, a -.Dq b +.Ql b partition for swap, a -.Dq d -partition for /var (usually 128MB), an -.Dq e +.Ql d +partition for +.Pa /var +(usually 128MB), an +.Ql e partition -for /var/tmp (usually 128MB), an -.Dq f -partition for /usr (usually around 2G), +for +.Pa /var/tmp +(usually 128MB), an +.Ql f +partition for +.Pa /usr +(usually around 2GB), and finally a -.Dq g -partition for /home (usually all remaining space). +.Ql g +partition for +.Pa /home +(usually all remaining space). Your mileage may vary. -.El .Pp -.Nm fdisk Fl BI Ar da0 +.Nm fdisk Fl BI Pa da0 .Pp .Nm -.Fl w -.Fl B -.Ar da0s1 +.Fl w B +.Pa da0s1 .Cm auto .Pp -.Pp .Nm .Fl e -.Ar da0s1 +.Pa da0s1 .Sh FILES .Bl -tag -width ".Pa /etc/disktab" -compact .It Pa /boot/boot @@ -461,8 +482,11 @@ Disk description file. The .Nm utility -uses an ASCII version of the label when examining, editing or restoring a disk -label. The format is: +uses an +.Tn ASCII +version of the label when examining, editing, or restoring a disk +label. +The format is: .Bd -literal -offset 4n # /dev/da1c: type: SCSI @@ -491,51 +515,56 @@ drivedata: 0 h: 962010 211920 vinum # (Cyl. 218*- 1211*) .Ed .Pp -Lines starting with a # mark are comments. Most of the other specifications are -no longer used. The ones which must still be set correctly are: +Lines starting with a +.Ql # +mark are comments. +Most of the other specifications are no longer used. +The ones which must still be set correctly are: .Pp -.Bl -hang -width 20n -.It Nm label +.Bl -inset +.It Ar label is an optional label, set by the .Ar packid option when writing a label. -.It Nm flags -Flags may be -.Ar removable , -.Ar ecc +.It Ar flags +may be +.Cm removable , ecc or -.Ar badsect . -.Ar removable +.Cm badsect . +.Cm removable is set for removable media drives, but no current .Fx driver evaluates this flag. -.Ar ecc +.Cm ecc is no longer supported; -.Ar badsect +.Cm badsect specifies that the drive can perform bad sector remapping. -.It Nm sectors/unit -describes the total size of the disk. This value must be correct. -.It Nm the partition table -This is the +.It Ar sectors/unit +describes the total size of the disk. +This value must be correct. +.It Ar "the partition table" +is the .Ux -partition table, not the Microsoft partition table described in +partition table, not the +.Tn DOS +partition table described in .Xr fdisk 8 . .El .Pp -The partition table can have up to 8 entries. It contains the following -information: -.Bl -hang -width 10n -.It identifier +The partition table can have up to 8 entries. +It contains the following information: +.Bl -tag -width indent +.It Ar # The partition identifier is a single letter in the range -.Dq a +.Ql a to -.Dq h . +.Ql h . By convention, partition -.Dq c +.Ql c is reserved to describe the entire disk. -.It size -is the size of the partition in sectors, +.It Ar size +The size of the partition in sectors, .Cm K (kilobytes - 1024), .Cm M @@ -543,51 +572,59 @@ is the size of the partition in sectors, .Cm G (gigabytes - 1024*1024*1024), .Cm % -(percentage of free space AFTER removing any fixed-size partitions other -than partition -.Dq c) , +(percentage of free space +.Em after +removing any fixed-size partitions other than partition +.Ql c ) , or .Cm * -(all remaining free space AFTER fixed-size and percentage -partitions). For partition -.Dq c , +(all remaining free space +.Em after +fixed-size and percentage partitions). +For partition +.Ql c , a size of .Cm * -indicates the entire disk. Lowercase versions of +indicates the entire disk. +Lowercase versions of .Cm K , M , and .Cm G are allowed. Size and type should be specifed without any spaces between them. .Pp -Example: 2097152, 1g, 1024m and 1048576k are all the same size +Example: 2097152, 1G, 1024M and 1048576K are all the same size (assuming 512-byte sectors). -.It offset -is the offset of the start of the partition from the beginning of the +.It Ar offset +The offset of the start of the partition from the beginning of the drive in sectors, or .Cm * to have .Nm calculate the correct offset to use (the end of the previous partition plus one, ignoring partition -.Dq c . +.Ql c . For partition -.Dq c , +.Ql c , .Cm * will be interpreted as an offset of 0. -.It fstype -describes the purpose of the partition. The example shows all currently used -partition types. -For UFS file systems and ccd partitions, use type +.It Ar fstype +Describes the purpose of the partition. +The example shows all currently used partition types. +For +.Tn UFS +file systems and +.Xr ccd 4 +partitions, use type .Cm 4.2BSD . For Vinum drives, use type .Cm vinum . Other common types are -.Cm unused +.Cm swap and -.Cm swap . +.Cm unused . By convention, partition -.Dq c +.Ql c represents the entire slice and should be of type .Cm unused , though @@ -596,51 +633,59 @@ does not enforce this convention. The .Nm utility -also knows about a number of other partition types, none of which are in current -use. -See the definitions starting with +also knows about a number of other partition types, +none of which are in current use. +(See the definitions starting with .Dv FS_UNUSED in -.Pa /usr/include/sys/disklabel.h -for more details. -.It fsize +.Aq Pa sys/disklabel.h +for more details.) +.It Ar fsize For .Cm 4.2BSD -and LFS file systems only, the fragment size. Defaults to 1024 for -partitions smaller than 1 GB, 4096 for partitions 1GB or larger. -.It bsize +and +.Tn LFS +file systems only, the fragment size. +Defaults to 1024 for partitions smaller than 1GB, +4096 for partitions 1GB or larger. +.It Ar bsize For .Cm 4.2BSD -and LFS file systems only, the block size. Defaults to 8192 for -partitions smaller than 1 GB, 16384 for partitions 1GB or larger. -.It bps/cpg +and +.Tn LFS +file systems only, the block size. +Defaults to 8192 for partitions smaller than 1GB, +16384 for partitions 1GB or larger. +.It Ar bps/cpg For .Cm 4.2BSD -file systems, the number of cylinders in a cylinder group. For LFS file -systems, the segment shift value. Defaults to 16 for -partitions smaller than 1 GB, 64 for partitions 1GB or larger. +file systems, the number of cylinders in a cylinder group. +For +.Tn LFS +file systems, the segment shift value. +Defaults to 16 for partitions smaller than 1GB, +64 for partitions 1GB or larger. .El .Pp The remainder of the line is a comment and shows the cylinder allocations based on the obsolete (but possibly correct) geometry information about the drive. -The asterisk (*) indicates that the partition does not begin or end exactly on a +The asterisk +.Pq Ql * +indicates that the partition does not begin or end exactly on a cylinder boundary. .Sh EXAMPLES -.Dl disklabel da0 +.Dl "disklabel da0s1" .Pp -Display the in-core label for -.Pa da0s1 -as obtained via +Display the in-core label for the first slice of the +.Pa da0 +disk, as obtained via .Pa /dev/da0s1 . -When reading a label, -.Fx -will allow you to specify the base disk name -even if the label resides on a slice. However, to be proper you should -specify the base disk name only if you are using a -.Dq dangerously-dedicated -label. Normally you specify the slice. +(If the disk is +.Dq dangerously-dedicated , +the base disk name should be specified, such as +.Pa da0 . ) .Pp -.Dl disklabel da0s1 > savedlabel +.Dl "disklabel da0s1 > savedlabel" .Pp Save the in-core label for .Pa da0s1 @@ -648,9 +693,9 @@ into the file .Pa savedlabel . This file can be used with the .Fl R -flag to restore the label at a later date. +option to restore the label at a later date. .Pp -.Dl disklabel -w -r /dev/da0s1 da2212 foo +.Dl "disklabel -w -r /dev/da0s1 da2212 foo" .Pp Create a label for .Pa da0s1 @@ -658,30 +703,36 @@ based on information for .Dq da2212 found in .Pa /etc/disktab . -Any existing bootstrap code will be clobbered. +Any existing bootstrap code will be clobbered +and the disk rendered unbootable. .Pp -.Dl disklabel -e -r da0s1 +.Dl "disklabel -e -r da0s1" .Pp Read the on-disk label for .Pa da0s1 , -edit it and reinstall in-core as well as on-disk. Existing bootstrap code is -unaffected. +edit it, and reinstall in-core as well as on-disk. +Existing bootstrap code is unaffected. .Pp -.Dl disklabel -e -r -n da0s1 +.Dl "disklabel -e -r -n da0s1" .Pp Read the on-disk label for .Pa da0s1 , -edit it, and display what the new label would be (in sectors). It does -NOT install the new label either in-core or on-disk. +edit it, and display what the new label would be (in sectors). +It does +.Em not +install the new label either in-core or on-disk. .Pp -.Dl disklabel -r -w da0s1 auto +.Dl "disklabel -r -w da0s1 auto" .Pp Try to auto-detect the required information from .Pa da0s1 , -and write a new label to the disk. Use another disklabel -e command to edit the +and write a new label to the disk. +Use another +.Nm Fl e +command to edit the partitioning and file system information. .Pp -.Dl disklabel -R da0s1 savedlabel +.Dl "disklabel -R da0s1 savedlabel" .Pp Restore the on-disk and in-core label for .Pa da0s1 @@ -689,7 +740,7 @@ from information in .Pa savedlabel . Existing bootstrap code is unaffected. .Pp -.Dl disklabel -R -n da0s1 label_layout +.Dl "disklabel -R -n da0s1 label_layout" .Pp Display what the label would be for .Pa da0s1 @@ -702,7 +753,7 @@ or .Cm * partition sizes. .Pp -.Dl disklabel -B da0s1 +.Dl "disklabel -B da0s1" .Pp Install a new bootstrap on .Pa da0s1 . @@ -710,38 +761,45 @@ The boot code comes from .Pa /boot/boot . On-disk and in-core labels are unchanged. .Pp -.Dl disklabel -w -B /dev/da0s1 -b newboot da2212 +.Dl "disklabel -w -B /dev/da0s1 -b newboot da2212" .Pp Install a new label and bootstrap. -The label is derived from disktab information for -.Dq da2212 +The label is derived from +.Xr disktab 5 +information for +.Dq da2212 , and installed both in-core and on-disk. -The bootstrap code comes from the files -.Pa /boot/newboot -.Pp -.Dl dd if=/dev/zero of=/dev/da0 bs=512 count=32 -.Dl fdisk -BI da0 -.Dl dd if=/dev/zero of=/dev/da0s1 bs=512 count=32 -.Dl disklabel -w -B da0s1 auto -.Dl disklabel -e da0s1 +The bootstrap code comes from the file +.Pa newboot +in the current working directory. +.Bd -literal -offset indent +dd if=/dev/zero of=/dev/da0 bs=512 count=32 +fdisk -BI da0 +dd if=/dev/zero of=/dev/da0s1 bs=512 count=32 +disklabel -w -B da0s1 auto +disklabel -e da0s1 +.Ed .Pp Completely wipe any prior information on the disk, creating a new bootable -disk with a DOS partition table containing one -.Dq whole-disk -slice. Then -initialize the slice, then edit it to your needs. The -.Pa dd -commands are optional, but may be necessary for some BIOSes to properly +disk with a +.Tn DOS +partition table containing one slice, covering the whole disk. +Initialize the label on this slice, +then edit it. +The +.Xr dd 1 +commands are optional, but may be necessary for some +.Tn BIOS Ns es +to properly recognize the disk. .Pp -This is an example disklabel that uses some of the new partition size types +This is an example disk label that uses some of the new partition size types such as .Cm % , M , G , and .Cm * , which could be used as a source file for -.Pp -.Dl disklabel -R ad0s1c new_label_file +.Dq Li "disklabel -R ad0s1c new_label_file" : .Bd -literal -offset 4n # /dev/ad0s1c: type: ESDI @@ -773,6 +831,7 @@ drivedata: 0 .Ed .Sh SEE ALSO .Xr ccd 4 , +.Xr md 4 , .Xr disklabel 5 , .Xr disktab 5 , .Xr boot0cfg 8 , @@ -783,35 +842,43 @@ The kernel device drivers will not allow the size of a disk partition to be decreased or the offset of a partition to be changed while it is open. Some device drivers create a label containing only a single large partition if a disk is unlabeled; thus, the label must be written to the -.Dq a -partition of the disk while it is open. This sometimes requires the desired -label to be set in two steps, the first one creating at least one other -partition, and the second setting the label on the new partition while shrinking -the -.Dq a +.Ql a +partition of the disk while it is open. +This sometimes requires the desired label to be set in two steps, +the first one creating at least one other partition, +and the second one setting the label on the new partition +while shrinking the +.Ql a partition. .Pp -On some machines the bootstrap code may not fit entirely in the area +On some machines, the bootstrap code may not fit entirely in the area allocated for it by some file systems. -As a result, it may not be possible to have file systems on some partitions -of a +As a result, +it may not be possible to have file systems on some partitions of a .Dq bootable disk. When installing bootstrap code, .Nm checks for these cases. -If the installed boot code would overlap a partition of type FS_UNUSED -it is marked as type FS_BOOT. +If the installed boot code would overlap a partition of type +.Dv FS_UNUSED , +it is marked as type +.Dv FS_BOOT . The .Xr newfs 8 -utility will disallow creation of file systems on FS_BOOT partitions. -Conversely, if a partition has a type other than FS_UNUSED or FS_BOOT, +utility will disallow creation of file systems on +.Dv FS_BOOT +partitions. +Conversely, if a partition has a type other than +.Dv FS_UNUSED +or +.Dv FS_BOOT , .Nm will not install bootstrap code that overlaps it. .Sh BUGS When a disk name is given without a full pathname, the constructed device name uses the -.Dq c +.Ql c partition. .Pp For the i386 architecture, the primary bootstrap sector contains @@ -831,18 +898,22 @@ or .Fl R , thus replacing the .Em fdisk -table by the dummy one in the bootstrap program. This is only of +table by the dummy one in the bootstrap program. +This is only of concern if the disk is fully dedicated, so that the -.Bx -disklabel +.Fx +disk label starts at absolute block 0 on the disk. .Pp The .Nm utility -does not perform all possible error checking. Warning *is* given if partitions -overlap; if an absolute offset does not match the expected offset; if the -.Dq c -partition does not start at 0 or does not cover the entire slice; if a -partition runs past the end of the device; and a number of other errors; but -no warning is given if space remains unused. +does not perform all possible error checking. +Warning is given if partitions overlap, +if an absolute offset does not match the expected offset, +if the +.Ql c +partition does not start at 0 or does not cover the entire slice, +if a partition runs past the end of the device, +and a number of other errors, +but no warning is given if space remains unused. |