osx man page for disklabel

disklabel(8)						    BSD System Manager's Manual 					      disklabel(8)

NAME
     disklabel -- manipulate and query an Apple Label disk label

SYNOPSIS
     disklabel -create disk-device [-msize=size] [property=value] [...]
     disklabel -status disk-device
     disklabel -properties disk-device [property[=value]] [...]
     disklabel -destroy disk-device

DESCRIPTION
     The disklabel utility manipulates ``Apple Label'' partition metadata.  ``Apple Label'' partitions allow for a disk device to have a consis-
     tent name, ownership, and permissions across reboots, even though uses a dynamic pseudofilesystem for /dev.

     The ``Apple Label'' partition uses a set of metadata (as a plist) in a reserved area of the partition.  This metadata describes the owner,
     name, and so forth.

     When -create is used, the -msize argument can specify the size of metadata area; the default is 128Kbytes.  The default size unit is bytes,
     but the following suffixes may be used to multiply by the given factor: ``b'' (512), ``k'' (1024), ``m'' (1048576), and ``g'' (1073741824).

     Although any key-value pair can be specified for the properties, certain keys are used by the system:

     owner-uid	 The user (as either a string or numeric value) to own the device.

     owner-gid	 The group (as either a string or numeric value) associated with the device.

     owner-mode  The permissions (as a numeric value) for the device.

     dev-name	 The name for the device.

     If the owner-uid and owner-gid properties are given as strings, the utility will attempt to look up the names (as users or groups, as appro-
     priate), and will store the numeric values in the metadata.  If it cannot find the names, and the values are not given as numbers, it will
     print an error, and not store the key/value pairs in the metadata.

     The owner-mode property may be given in decimal, or in octal by using a preceding ``0'' (e.g., ``0666'').

     Any property may be forced to be treated as a string by enclosing it in double-quotation marks; bear in mind that shell escapes will probably
     be necessary in this sitation.

     The -properties directive can print out all keys (if no arguments are given), a requested set of keys (if a list of key names is given), or
     can modify (or add) keys (if a key-value pairs are given).

     also maintains a checksum of the metadata; the -status directive verifies this checksum.

EXAMPLES
     The following example will create a device with 1MByte of metadata area, owned by fred, with a device name of fred, and be writable by fred:

	   disklabel -create /dev/rdisk1s1 -msize=1M owner-uid=fred dev-name=fred owner-mode=0644

     The following example will then print out the key-value pairs from the above:
	   disklabel -properties /dev/rdisk1s1

SEE ALSO
     pdisk(8)

BSD
								 September 3, 2004							       BSD