LABELDISK — User Commands

NAME

labeldisk − read and write a disk’s label

SYNOPSIS

labeldisk[−from fromDevice] [−w] [−q] [−sun] [−dec] [−new] device

OPTIONS

−from fromDevice
Read the label from this device.

−wWrite a new label.

−qWrite a new label quickly, without prompting for partition information.

−sunWrite out a Sun label. The default is to write whatever type of label was read.

−decWrite out a Dec label.

−newIgnore any old label.

deviceThe device file with the disk label. Without -from it is the device that the label is read from and written to, otherwise it is the device that is written to.

DESCRIPTION

This reads the disk label and verifies its checksum. If the -from fromDevice option is present then the disk label is read from the fromDevice, and the device argument becomes the device to which the label is written to.

If the −w option is present labeldisk interactively prompts for partition information. After this the user is presented with the new label and given the opportunity to commit the change or abort it. The user is also given the chance to write the label to all of the valid partitions found on the device. “valid” means that the partition has a positive number of cylinders associated with it, and that a file system exists on the partition. If a partition on the disk is not “valid”, then it is skipped. An attempt is made to write the label to the raw disk in the improbable case that no valid partition starts on cylinder 0. If labeldisk was not able to write the label to the raw disk or to a partition that begins at cylinder 0, then a warning is issued to that effect.

The -q option turns off the prompting for partition information only. This is useful for copying a label from one partition on one device to other partitions on the same or different device if the user knows that the label on the from device has the correct information. Overrides the -w option.

The -dec option converts the label being written to a dec label.

The -sun option converts the label being written to a dec label.

The -new option ignores any label read, and creates a new one instead. If either the -dec or the -sun option is specified then the new label created is of the specified type.

Each disk is divided into 8 partitions, named “ai” thru “gi”. Each partition is specified with a starting cylinder number and the number of cylinders it contains. Unused partitions are indicated with a zero size. Partitions can overlap, but overlapping partitions should never be used simultaneously! Traditionally partition “ai” is a small partition suitable for the root or a small /tmp. Partition “bi” is a slightly larger system suitable for a single machine’s swap directory. Partition “ci” is a single large partition that specifies the whole disk. Partitions “di” and “ei” are often used as large partitions beyond “ai” and “bi”. Partition “gi” is usually set up as all the space after “ai” and “bi”. Partitions “fi” and “hi” usually aren’t used, but they can be.

Partitions are useful to quarantine different sets of users from one another, although they are a pain to change once a filesystem has been created on them. Changing them requires recreating any affected filesystems.

KEYWORDS

disk, label