FreeBSD Man Pages

sunlabel(8)

SYNOPSIS

     sunlabel [-r] [-c | -h] disk
     sunlabel -B [-b boot1] [-n] disk
     sunlabel -R [-B [-b boot1]] [-r] [-n] [-c] disk protofile
     sunlabel -e [-B [-b boot1]] [-r] [-n] [-c] disk
     sunlabel -w [-B [-b boot1]] [-r] [-n] [-c] disk type

DESCRIPTION

     The sunlabel utility installs, examines or modifies the Sun OpenBoot PROM
     label on a disk.  In addition, sunlabel can install bootstrap code.

   Introduction
     The label occupies the first sector (i.e., 512 bytes) of each disk.  It
     starts with a textual description which by convention also mentions the
     disk geometry in textual form (number of cylinders, alternate cylinders,
     heads, and sectors per track), optionally followed by a table of
     SVR4-compatible VTOC tags and flags per partition, followed by the parti-
     tion table itself.  Finally, a checksum is recorded to ensure the label
     has not been tampered with.

     The Sun OpenBoot PROM label allows for 8 disk partitions.	The partition
     table lists the starting cylinder of the partition, plus the size of the
     partition in 512-byte sectors.  Thus, partitions in the Sun OpenBoot PROM
     must always start at a cylinder boundary (for whatever geometry emulation
     has been chosen).

     The optional SVR4-compatible VTOC tag and flags table is not used by the
     FreeBSD kernel.  It is maintained solely for compatibilty with the
     Solaris operating system that might share disks with FreeBSD on the same
     hardware platform.

     The Sun OpenBoot PROM label is natively understood by the underlying
     hardware, which can bootstrap from a single partition entry, as opposed
     to the very first block(s) of the entire disk as on many other hardware
     platforms.

     Note that the hardware platform mandates that two cylinders are set aside
     as alternate cylinders which are not available to user programs (and not
     even through the ``backup'' partition).

   Options
     Options are listed in alphabetical order here.  Note that only those
     option combinations listed under SYNOPSIS are allowable.

     -b bootpath  Specify that bootpath is to be used as the boot image,
		  rather than the default of /boot/boot1.

     -B 	  Install bootstrap code onto the disk.  Note that since the
		  underlying hardware platform bootstraps from partitions, not
		  disks, this operation is only useful if there is a partition
		  starting at offset 0.

     -c 	  Use cylinders for partition size display rather than

     -h 	  When displaying the label, make the partition size and off-
		  set values ``human readable''.  The displayed numbers will
		  get a suffix of `B' for bytes, `K' for 1024 bytes each, `M'
		  for 1048576 bytes each, or `G' for 1073741824 bytes each
		  appended.  Note that due to possible rounding errors, proto-
		  type files obtained using the -h option are not suited for
		  re-installing using the -R option.

     -n 	  No changes.  All operations, checks etc., are performed nor-
		  mally, but nothing is written to disk.

     -r 	  Obsolete option that used to indicate that the operation
		  should be done directly on disk, as opposed through the
		  respective kernel services.  Ignored.

     -R 	  Restore label from the prototype in protofile.  A prototype
		  file is simply the textual representation of the label as
		  printed using the first form of the sunlabel utility shown
		  in the SYNOPSIS.  Note that the -c option used to obtain the
		  prototype must match the option used when restoring the
		  label (both present, or both absent).

     -w 	  Write mode.  Suitable to write an initial label to disk.
		  The type argument used to be an entry into a table of prede-
		  fined labels, but this functionality is not supported by
		  sunlabel.  Instead, the only allowable type argument is the
		  string ``auto'', indicating that an automatically created
		  label should be written to disk.  This automatism will try
		  to create an initial label that fits as best as possible
		  into the available disk capacity.

     If neither of the -e, -R, or -w options are present, the existing label
     for disk will be printed to standard output.

     The disk argument must be given as a plain disk name, without any leading
     /dev/.

   Edit mode
     In edit mode, the existing label from disk will be read, and put into a
     template file.  The command referenced by the EDITOR environmental vari-
     able will be started to allow the user to edit the label.	The label is
     then checked and examined for any errors.	If no errors have been found,
     the new label is written to disk.	If there were any errors, a message is
     printed to standard error output, and the user is given the opportunity
     to edit the template file again.  If accepted, editing starts over.  If
     declined, no changes will be written to disk.

     The label presented for editing is the same as the standard printout,
     with some added hints about the possible options to specify the sector
     size and starting cylinder.  There are two areas in the template that can
     be edited:

     Textual label, geometry emulation
	     The line
		   text: XXXX cyl CC alt 2 hd HH sec SS
	     represents the label text.  It must be retained exactly in the
	     form shown.  The editable text XXXX is a simple (non-whitespace)

		   (CC + 2) * HH * SS
	     must be less than or equal to the total number of sectors of the
	     disk (which is given as a hint in a comment field).

     Partition entries
	     Partition entries start with a letter from `a' through `h', imme-
	     diately followed by a colon, followed by the size of this parti-
	     tion, and the starting cylinder of the partition.	The unit of
	     the size field defaults to sectors, or to cylinders if the -c
	     option is in effect.  Alternatively, a different unit may be
	     specified by appending `s' for (512-byte) sectors, `c' for cylin-
	     ders, `k' for kilobytes, `m' for megabytes, or `g' for gigabytes.
	     The last partition entry may specify the size as `*' to indicate
	     that this entry should consume the rest of disk not consumed by
	     any other partition so far.

	     The start of partition is always taken as a cylinder number
	     (starting at 0) since this is what the underlying hardware uses.
	     Alternatively, specifying it as `*' will make the computation
	     automatically chose the nearest possible cylinder boundary.

	     Partition `c' must always be present, must start at 0, and must
	     cover the entire disk (without considering the alternate cylin-
	     ders though).

	     Optionally, each partition entry may be followed by an SVR4-com-
	     patible VTOC tag name, and a flag description.  The following
	     VTOC tag names are known:

		   name 	 value	  comment
		   unassigned	 0x00
		   boot 	 0x01
		   root 	 0x02
		   swap 	 0x03
		   usr		 0x04
		   backup	 0x05	  c partition, entire disk
		   stand	 0x06
		   var		 0x07
		   home 	 0x08
		   altsctr	 0x09	  alternate sector partition
		   cache	 0x0a	  Solaris cachefs partition
		   VxVM_pub	 0x0e	  VxVM public region
		   VxVM_priv	 0x0f	  VxVM private region

	     The following VTOC flags are known:

		   name    value    comment
		   wm	   0x00     read/write, mountable
		   wu	   0x01     read/write, unmountable
		   rm	   0x10     read/only, mountable
		   ru	   0x11     read/only, unmountable

	     Optionally, both the tag and/or the flag name may be specified
	     numerically, using standard `C' numerial notation (prefix `0x'
	     for hexadecimal numbers, `0' for octal numbers).  If the flag
	     field is omitted, it defaults to `wm'.  If the tag field is also
	     omitted, it defaults to ``unassigned''.  If none of the parti-
	     tions lists any VTOC tag/flags, no SVR4-compatible VTOC elements

     against other partitions will be warned still but do not cause a rejec-
     tion of the label.  That way, encapsulated disks of volume management
     software are acceptable as long as the volume management partitions are
     clearly marked as unmountable.

     Any other fields in the label template are informational only, and will
     not be parsed when reading the label.

     Note that when changing the geometry emulation by editing the textual
     description line, all partition entries will be considered based on the
     new geometry emulation.

ENVIRONMENT

     EDITOR  Name of the command to edit the template file in edit-mode.
	     Defaults to vi(1).

FILES

     /boot/boot1  Default boot image.

SEE ALSO

     vi(1), geom(4), bsdlabel(8)

HISTORY

     The sunlabel utility appeared in FreeBSD 5.1.

AUTHORS

     The sunlabel utility was written by Jake Burkholder, modeling it after
     the bsdlabel(8) command available on other architectures.

     This man page was initially written by David O'Brien, and later substan-
     tially updated by Jorg Wunsch.

BUGS

     Installing bootstrap code onto an entire disk is merely pointless.
     sunlabel should rather support installing bootstrap code into a partition
     instead.

     The ``auto'' layout algorithm could be smarter.  By now, it tends to emu-
     late fairly large cylinders which due to the two reserved alternate
     cylinders causes a fair amount of wasted disk space.

FreeBSD 5.4			 June 1, 2004			   FreeBSD 5.4

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