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disklabel(4) [osf1 man page]

disklabel(4)						     Kernel Interfaces Manual						      disklabel(4)

disklabel - Disk pack label SYNOPSIS
#include <sys/disklabel.h> DESCRIPTION
Each disk or disk pack on a system may contain a disk label which provides detailed information about the geometry of the disk and the par- titions into which the disk is divided. It should be initialized when the disk is formatted, and may be changed later with the disklabel program. This information is used by the system disk driver and by the bootstrap program to determine how to program the drive and where to find the file systems on the disk partitions. Additional information is used by the file system in order to use the disk most effi- ciently and to locate important file system information. The description of each partition contains an identifier for the partition type (standard file system, swap area, etc.). The file system updates the in-core copy of the label if it contains incomplete information about the file system. The label is located in sector number LABELSECTOR of the drive, usually sector 0 (zero) where it may be found without any information about the disk geometry. It is at an offset LABELOFFSET from the beginning of the sector, to allow room for the initial bootstrap. The disk sector containing the label is normally made read-only so that it is not accidentally overwritten by pack-to-pack copies or swap opera- tions; the DIOCWLABEL ioctl, which is done as needed by the disklabel program, allows modification of the label sector. A copy of the in-core label for a disk can be obtained with the DIOCGDINFO ioctl; this works with a file descriptor for a block or charac- ter (raw) device for any partition of the disk. The in-core copy of the label is set by the DIOCSDINFO ioctl. The offset of a partition cannot generally be changed, nor made smaller while it is open. One exception is that any change is allowed if no label was found on the disk, and the driver was able to construct only a skeletal label without partition information. Finally, the DIOCWDINFO ioctl operation sets the in-core label and then updates the on-disk label; there must be an existing label on the disk for this operation to succeed. Thus, the initial label for a disk or disk pack must be installed by writing to the raw disk. All of these operations are normally done using the disklabel program. RELATED INFORMATION
Files: disktab(4) Commands: disklabel(8) delim off disklabel(4)

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extendfs(8)						      System Manager's Manual						       extendfs(8)

extendfs - Extends UFS file systems SYNOPSIS
/sbin/extendfs [- s] [disk_blocks] device_name DESCRIPTION
Use the extendfs command to increase the storage space in a UFS file system. The file system must not be mounted when you perform this operation. To extend a mounted (in use) UFS file system, use the mount command with the -o extend option. The procedure for increasing the storage space of a UFS file system is as follows: Look at the contents the /etc/fstab file to identify the disk partition that maps to the file system. Ensure that there is available storage space on the target disk as follows: If LSM is in use on your system, use LSM commands to increase the size of the LSM volume as described in the Logical Storage Manager guide. If LSM is not in use on your system, use the disklabel command or the diskconfig graphical user interface to check the current size and use of partitions on the disk. If there is adequate space on an adjacent partition, use the disklabel command to write the current label to a file as fol- lows: # disklabel -r dsk4 > d4label Edit the disklabel file to change the size of the partition on which your UFS file system resides. Increase the number of disk blocks on the partition and decrease the disk block size of the adjacent partition by an equivalent number. Use the disklabel command with the -R option to write the revised label to the raw disk as follows: # disklabel -R /dev/rdisk/dsk4 d4label When the disk label is revised, extend the file system using the extendfs command. You can either use the full extent of the newly sized partition or extend the file system in stages. The following example commands show both methods. To extend the file system to use all the available space, you specify the disk partition on which the file system resides, as follows: # extendfs /dev/disk/dsk4g To extend the file system to use only part of the available space, you specify a number of disk blocks, as follows: # extendfs -s 300000 /dev/disk/dsk4g The remainder of the extended partion is reserved for future use. You can extend a file system as many times as necessary, up to the physical limit of the storage device. When no more space is available on the storage device, you must back up the file system using the dump command and restore the file system to a storage device that has more available space. Once you have extended a file system, the operation cannot be reversed except by a back up and restore operation. Use the dump command to back up the file system. You can then reset the partition sizes manually and restore the file system to the storage device. ERRORS
The disklabel command produces output similar to that of the newfs command. If a list of disk blocks is not displayed on the terminal, the command has failed. Verify the partition settings and the mount status of the target file system. The disklabel command does not permit you to overwrite a partition if it is in use. Refer to the disklabel(8) reference page for more information on label errors. FILES
Specifies the command path. RELATED INFORMATION
diskconfig(8), disklabel(8), mount(8), and fstab(4). extendfs(8)

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