lvextend(1M)

NAME

lvextend — increase space, increase mirrors for LVM logical volume

SYNOPSIS

/usr/sbin/lvextend [-A autobackup] {-l le_number | -L lv_size | -m mirror_copies} lv_path [pv_path ... | pvg_name ...]

Remarks

Mirrored disk operations require the installation of the optional HP MirrorDisk/UX software, which is not included in the standard HP-UX operating system.

lvextend cannot be performed if the volume group is activated in shared mode.

DESCRIPTION

The lvextend command can increase a logical volume's allocated extents, or increase its number of mirrored copies.

Other logical volume characteristics can be modified with the lvchange and lvreduce commands (see lvchange(1M) and lvreduce(1M)).

To limit the allocation to specific physical volumes, specify the physical volume names as pv_path arguments or specify the physical volume group names as pvg_name arguments. Otherwise, all of the physical volumes in a volume group are available for allocating new physical extents. LVM always ensures that physical extent allocation can satisfy the current allocation policy or policies. If a physical volume is not suitable for use with a certain allocation policy, it is not used during physical extent allocation, even it is specified in a pv_path argument or indirectly in a pvg_name argument.

The pvg_name argument is allowed only if one of the allocation policies of the logical volume is PVG-strict.

Options and Arguments

The -m option is only meaningful if the optional HP MirrorDisk/UX software has been installed.

lvextend recognizes the following options and arguments:

lv_path

The block device path name of a logical volume.

pv_path

The block device path name of a physical volume.

pvg_name

The name of a physical volume group (see lvmpvg(4)).

-A autobackup

Set automatic backup for this invocation of this command. autobackup can have one of the following values:

y

Automatically back up configuration changes made to the logical volume. This is the default.

After this command executes, the vgcfgbackup command (see vgcfgbackup(1M)) is executed for the volume group to which the logical volume belongs.

n

Do not back up configuration changes this time.

-l le_number

Increase the space allocated to the logical volume, specified in logical extents. le_number is a decimal value greater than the current number of logical extents, in the range 1 to 65535 (the implementation limit).

One, and only one, -l, -L, or -m option must be supplied.

-L lv_size

Increase the space allocated to the logical volume, specified in megabytes. lv_size is a decimal value greater than the current logical volume size, in the range 1 to 16777216 (the implementation limit). lv_size is rounded up to the nearest multiple of the logical extent size, equivalent to the physical extent size defined for the volume group by the vgcreate command (see vgcreate(1M)).

One, and only one, -l, -L, or -m option must be specified.

-m mirror_copies

Set the number of mirror copies allocated for each logical extent. A mirror copy contains the same data as the original. mirror_copies can have the value 1 or 2. It must be greater than the current value.

Data in the new copies is synchronized. The synchronization process can be time consuming, depending on hardware characteristics and the amount of data.

One, and only one, -l, -L, or -m option must be specified.

Striped Logical Volume considerations

Striped and mirrored logical volumes are supported.

An increase in size of a striped logical volume is done by increments of stripes logical extents. One increment corresponds to stripes physical extents if the volume is not mirrored or to stripes * (mirror_copies + 1) physical extents if the volume is mirrored. stripes is the number of disks the logical volume is striped across. It is set with the option -i stripes of the lvcreate command. mirror_copies is the number of mirror copies allocated for each extent. It is set with the -m option of the lvcreate and lvextend commands. LVM striped logical volumes are always allocated using the strict or PVG-strict allocation policies. Each physical extent of an increment is allocated on a different physical volume in the volume group.

A size increase of a striped volume requires at least stripes (or stripes * (mirror_copies + 1) if the volume is mirrored) physical volumes with adequate free space and meeting the allocation policy.

An increase of the number of mirror copies of a striped volume requires at least (stripes times the number of copies to add) physical volumes with adequate free space and meeting the allocation policy.

EXTERNAL INFLUENCES

Environment Variables

LANG determines the language in which messages are displayed.

If LANG is not specified or is null, it defaults to "C" (see lang(5)).

If any internationalization variable contains an invalid setting, all internationalization variables default to "C" (see environ(5)).

EXAMPLES

Increase the number of the logical extents of a logical volume to 100:

lvextend -l 100 /dev/vg01/lvol3 

Increase the logical volume size to 400 MB:

lvextend -L 400 /dev/vg01/lvol4 

Allocate two mirrors (that is, two copies of the original) for each logical extent of a logical volume:

lvextend -m 2 /dev/vg01/lvol5 

Mirror a logical volume onto a particular physical volume.

lvextend -m 1 /dev/vg00/lvol3 /dev/dsk/c0t3d0 

Increase the size of a file system existing on a logical volume.

First, increase the size of the logical volume.

lvextend -L 400 /dev/vg06/lvol3

Unmount the file system.

umount /dev/vg06/lvol3

Extend the file system to occupy the entire (larger) logical volume.

extendfs /dev/vg06/rlvol3

Remount the file system.

mount /dev/vg06/lvol3 /mnt

WARNINGS

The creation of striped and mirrored logical volume(s) may prevent the import and activation of the volume group on an earlier HP-UX release. See lvcreate(1M) on the earlier release to see if it explicitly states that striping and mirroring is supported. If the striped and mirrored logical volumes of the volume group are removed or un-mirrored, the volume group becomes again compatible with the older HP-UX releases.