disklabel(8) [osx man page]
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
Check Out this Related Man Page
CCD(4) BSD Kernel Interfaces Manual CCD(4) NAME
ccd -- Concatenated disk driver SYNOPSIS
pseudo-device ccd [count] DESCRIPTION
The ccd driver provides the capability of combining one or more disks/partitions into one virtual disk. This document assumes that you're familiar with how to generate kernels, how to properly configure disks and pseudo-devices in a kernel con- figuration file, and how to partition disks. Note that the 'raw' partitions of the disks must not be combined. Each component partition should be offset at least one cylinder from the beginning of the component disk. This avoids potential conflicts between the component disk's disklabel and the ccd's disklabel. The kernel will only allow component partitions of type FS_CCD. But for now, it allows partition of all types since some port lacks support of an on- disk BSD disklabel. The partition of FS_UNUSED may be rejected because device driver of component disk will refuse it. In order to compile in support for the ccd, you must add a line similar to the following to your kernel configuration file: pseudo-device ccd 4 # concatenated disk devices The count argument is how many ccds memory is allocated for at boot time. In this example, no more than 4 ccds may be configured. A ccd may be either serially concatenated or interleaved. To serially concatenate the partitions, specify the interleave factor of 0. If a ccd is interleaved correctly, a ``striping'' effect is achieved, which can increase performance. Since the interleave factor is expressed in units of DEV_BSIZE, one must account for sector sizes other than DEV_BSIZE in order to calculate the correct interleave. The kernel will not allow an interleave factor less than the size of the largest component sector divided by DEV_BSIZE. Note that best performance is achieved if all component disks have the same geometry and size. Optimum striping cannot occur with different disk types. Also note that the total size of concatenated disk may vary depending on the interleave factor even if the exact same components are concate- nated. And an old on-disk disklabel may be read after interleave factor change. As a result, the disklabel may contain wrong partition geometry and will cause an error when doing I/O near the end of concatenated disk. There is a run-time utility that is used for configuring ccds. See ccdconfig(8) for more information. WARNINGS
If just one (or more) of the disks in a non-mirrored ccd fails, the entire file system will be lost. FILES
/dev/{,r}ccd* ccd device special files. SEE ALSO
config(1), MAKEDEV(8), ccdconfig(8), fsck(8), mount(8), newfs(8) HISTORY
The concatenated disk driver was originally written at the University of Utah. BSD
March 5, 2004 BSD