From c99208647479c0b824d2424b1192f105dabace2b Mon Sep 17 00:00:00 2001 From: jkh Date: Tue, 31 Oct 2000 07:07:39 +0000 Subject: Add support for virgin disklabels Submitted by: dillon --- sbin/disklabel/disklabel.8 | 168 +++++++++++++++++++++++++++++++++++++-------- 1 file changed, 138 insertions(+), 30 deletions(-) (limited to 'sbin/disklabel/disklabel.8') diff --git a/sbin/disklabel/disklabel.8 b/sbin/disklabel/disklabel.8 index 936618f..5a1871b 100644 --- a/sbin/disklabel/disklabel.8 +++ b/sbin/disklabel/disklabel.8 @@ -48,7 +48,7 @@ .Nm disklabel .Fl w .Op Fl r -.Ar disk Ar disktype +.Ar disk Ar disktype/auto .Oo Ar packid Oc .Nm disklabel .Fl e @@ -69,7 +69,7 @@ .Fl s Ar boot2 .Oc .Ar disk -.Oo Ar disktype Oc +.Oo Ar disktype/auto Oc .Nm disklabel .Fl w .Fl B @@ -77,7 +77,7 @@ .Fl b Ar boot1 .Fl s Ar boot2 .Oc -.Ar disk Ar disktype +.Ar disk Ar disktype/auto .Oo Ar packid Oc .Nm disklabel .Fl R @@ -87,7 +87,7 @@ .Fl s Ar boot2 .Oc .Ar disk Ar protofile -.Oo Ar disktype Oc +.Oo Ar disktype/auto Oc .Sh DESCRIPTION .Nm Disklabel installs, examines or modifes the label on a disk drive or pack. When writing @@ -116,15 +116,23 @@ is described under each command. All .Nm disklabel forms require a disk device name, which should always be the raw -.if t ``complete'' (or ``c'') -.if n "complete" (or "c") -partition, for example -.Pa /dev/da0c . +device name representing the disk or slice. For example +.Pa da0 +represents the entire disk irregardless of any DOS partitioning, +and +.Pa da0s1 +represents a slice. Some devices, most notably +.Ar ccd , +require that the +.if t ``whole-disk'' (or ``c'') +.if n "whole-disk" (or "c") +partition be specified. For example +.Pa ccd0c . +You do not have to include the +.Pa /dev/ +path prefix when specifying the device. .Nm -understands the abbreviation -.Pa da0 , -which it converts internally to -.Pa /dev/da0c . +will automatically prepend it. .Ss Reading the disk label .Pp To examine or save the label on a disk drive, use @@ -151,7 +159,9 @@ If the .Fl r flag is given, .Nm -reads the label from the raw disk and displays it. +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 To write a standard label, use the form @@ -159,9 +169,15 @@ To write a standard label, use the form .Nm disklabel .Fl w .Op Fl r -.Ar disk Ar disktype +.Ar disk Ar disktype/auto .Oo Ar packid Oc .Pp +.Nm disklabel +.Fl w +.Op Fl r +.Ar disk +auto +.Pp The required arguments to .Nm are the drive to be labeled and the drive type as described in the @@ -202,6 +218,20 @@ disk is the only supported operation, and the .Ar disk itself must be provided as the canonical name, i.e. not as a full path name. +.Pp +PC-based systems have special requirements in order for the BIOS to properly +recognize a FreeBSD disklabel. Older systems may require what is known as +a ``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 slice using +.Ar fdisk +and then create a FreeBSD disklabel 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 +described later on in this manual page. .Ss Editing an existing disk label .Pp To edit an existing disk label, use the form @@ -262,7 +292,16 @@ command .Pp The final three forms of .Nm -are used to install bootstrap code: +are used to install bootstrap code. If you are creating a +``dangerously-dedicated'' partition 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 slice name such as +.Pa da0s1 . +Making a partition 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 FreeBSD bootblocks in the slice. .Pp .Nm disklabel .Fl B @@ -274,6 +313,11 @@ are used to install bootstrap code: .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 ``dangerously-dedicated'' disk, such as +.Ar da0 . +This command is typically run on a slice such as +.Ar da0s1 . .Pp .Nm disklabel .Fl w @@ -288,6 +332,8 @@ This form installs the bootstrap only. It does not change the disk label. .if t This form corresponds to the ``write label'' command described above. .if n This form corresponds to the "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 ``dangerously-dedicated'' +label. This command is normally run on a slice rather then a base disk. .Pp .Nm disklabel .Fl R @@ -302,6 +348,8 @@ In addition to writing a new volume label, it also installs the bootstrap. .if t This form corresponds to the ``restore label'' command described above. .if n This form corresponds to the "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 ``dangerously-dedicated'' +label. This command is normally run on a slice rather then a base disk. .Pp The bootstrap commands always access the disk directly, so it is not necessary to specify the @@ -343,6 +391,49 @@ and for the standard stage1 and stage2 boot images (details may vary on architectures like the Alpha, where only a single-stage boot is used). .El +.Ss Initializing/Formatting a bootable disk from scratch +.Pp +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 non-FreeBSD slices. +.Bl -enum +.It +Use +.Ar fdisk +to initialize the DOS partition table, creating a real whole-disk slice to +hold the FreeBSD disklabel, and installing a master boot record. +.It +Use +.Ar disklabel +to initialize a virgin FreeBSD disklabel and install FreeBSD boot blocks . +.It +Use +.Ar disklabel +to edit your newly created label, addiing appropriate partitions. +.It +Finally newfs the filesystem partitions you created in the label. A typical +disklabel partiioning scheme would be to have an ``a'' partition +of approximately 128MB to hold the root filesystem, a ``b'' partition for +swap, a ``d'' partition for /var (usually 128MB), an ``e'' partition +for /var/tmp (usually 128MB), an ``f'' partition for /usr (usually around 2G), +and finally a ``g'' partition for /home (usally all remaining space). +Your mileage may vary. +.El +.Pp +.Nm fdisk -BI da0 +.Pp +.Nm disklabel +.Fl w +.Fl r +.Fl B +.Ar da0s1 +auto +.Pp +.Pp +.Nm disklabel +.Fl e +.Ar da0s1 +.Pp .Sh FILES .Bl -tag -width Pa -compact .It Pa /etc/disktab @@ -445,63 +536,67 @@ cylinder boundary. .Dl disklabel da0 .Pp Display the in-core label for -.Pa da0 +.Pa da0s1 as obtained via -.Pa /dev/da0c . +.Pa /dev/da0s1 . +When reading a label, FreeBSD 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 ``dangerously-dedicated'' +label. Normally you specify the slice. .Pp -.Dl disklabel da0 > savedlabel +.Dl disklabel da0s1 > savedlabel .Pp Save the in-core label for -.Pa da0 +.Pa da0s1 into the file .Pa savedlabel . This file can be used with the .Fl R flag to restore the label at a later date. .Pp -.Dl disklabel -w -r /dev/da0c da2212 foo +.Dl disklabel -w -r /dev/da0s1 da2212 foo .Pp Create a label for -.Pa da0 +.Pa da0s1 based on information for .if t ``da2212'' found in .if n "da2212" found in .Pa /etc/disktab . Any existing bootstrap code will be clobbered. .Pp -.Dl disklabel -e -r da0 +.Dl disklabel -e -r da0s1 .Pp Read the on-disk label for -.Pa da0 , +.Pa da0s1 , edit it and reinstall in-core as well as on-disk. Existing bootstrap code is unaffected. .Pp -.Dl disklabel -r -w da0 auto +.Dl disklabel -r -w da0s1 auto .Pp Try to auto-detect the required information from -.Pa da0 , +.Pa da0s1 , and write a new label to the disk. Use another disklabel -e command to edit the partitioning and file system information. .Pp -.Dl disklabel -R da0 savedlabel +.Dl disklabel -R da0s1 savedlabel .Pp Restore the on-disk and in-core label for -.Pa da0 +.Pa da0s1 from information in .Pa savedlabel . Existing bootstrap code is unaffected. .Pp -.Dl disklabel -B da0 +.Dl disklabel -B da0s1 .Pp Install a new bootstrap on -.Pa da0 . +.Pa da0s1 . The boot code comes from .Pa /boot/boot1 and possibly .Pa /boot/boot2 . On-disk and in-core labels are unchanged. .Pp -.Dl disklabel -w -B /dev/da0c -b newboot1 -s newboot da2212 +.Dl disklabel -w -B /dev/da0s1 -b newboot1 -s newboot da2212 .Pp Install a new label and bootstrap. .if t The label is derived from disktab information for ``da2212'' and @@ -511,6 +606,19 @@ The bootstrap code comes from the files .Pa /boot/newboot1 and .Pa /boot/newboot2 . +.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 -r -B da0s1 auto +.Dl disklabel -e da0s1 +.Pp +Completely wipe any prior information on the disk, creating a new bootable +disk with a DOS partition table containing one ``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 +recognize the disk. .Sh SEE ALSO .Xr disklabel 5 , .Xr disktab 5 , -- cgit v1.1