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AIX Version 4.3 Commands Reference, Volume 3

mklvcopy Command

Purpose

Provides copies of data within the logical volume.

Syntax

mklvcopy [ -a Position ] [ -e Range ] [ -k ] [ -m MapFile ] [ -s Strict ] [ -u UpperBound ] LogicalVolume Copies [ PhysicalVolume ... ]

Description

The mklvcopy command increases the number of copies in each logical partition in LogicalVolume. This is accomplished by increasing the total number of physical partitions for each logical partition to the number represented by Copies. The LogicalVolume parameter can be a logical volume name or logical volume ID. You can request that the physical partitions for the new copies be allocated on specific physical volumes (within the volume group) with the PhysicalVolume parameter; otherwise, all the physical volumes within the volume group are available for allocation.

The logical volume modified with this command uses the Copies parameter as its new copy characteristic. The data in the new copies are not synchronized until one of the following occurs: the -k option is used, the volume group is activated by the varyonvg command, or the volume group or logical volume is synchronized explicitly by the syncvg command. Individual logical partitions are always updated as they are written to.

The default allocation policy is to use minimum numbering of physical volumes per logical volume copy, to place the physical partitions belong to a copy as contiguously as possible, and then to place the physical partitions in the desired region specified by the -a flag. Also, by default, each copy of a logical partition is placed on a separate physical volume.

Notes:
  1. This command fails on a striped logical volume, mirroring is not possible.
  2. To use this command, you must either have root user authority or be a member of the system group.

You can use the Web-based System Manager Volumes application (wsm lvm fast path) to run this command. You could also use the System Management Interface Tool (SMIT) smit mklvcopy fast path to run this command.

Flags

-a Position Sets the intra-physical volume allocation policy (the position of the logical partitions on the physical volume). The Position variable can be one of the following:
m Allocates logical partitions in the outer middle section of each physical volume. This is the default position.
c Allocates logical partitions in the center section of each physical volume.
e Allocates logical partitions in the outer edge section of each physical volume.
ie Allocated logical partitions in the inner edge section of each physical volume.
im Allocates logical partitions in the inner middle section of each physical volume.
-e Range Sets the inter-physical volume allocation policy (the number of physical volumes to extend across, using the volumes that provide the best allocation). The Range value is limited by the Upperbound variable (set with the -u flag), and can be one of the following:
x Allocates across the maximum number of physical volumes.
m Allocates logical partitions across the minimum number of physical volumes. This is the default for the -e flag.
-k Synchronizes data in the new partitions.
-m MapFile Specifies the exact physical partitions to allocate. Partitions are used in the order given by the file designated by the MapFile parameter. Used partitions in the file are skipped. All physical partitions belonging to a copy are allocated before allocating for the next copy. The MapFile format is: 
PVname:PPnum1[-PPnum2]

where PVname is a physical volume name (for example, hdisk0). It is one record per physical partition or a range of consecutive physical partitions.

PVname Name of the physical volume as specified by the system.
PPnum Physical partition number.
-s Strict Determines the strict allocation policy. Copies of a logical partition can be allocated to share or not to share the same physical volume. The Strict variable can be one of the following:
y Sets a strict allocation policy, so copies for a logical partition cannot share the same physical volume. This is the default for the -s flag.
n Does not set a strict allocation policy, so copies for a logical partition can share the same physical volume.
-u UpperBound Sets the maximum number of physical volumes for new allocation. The value must be between one and the total number of physical volumes. The default is the total number of physical volumes in the volume group.

Example

To add physical partitions to the logical partitions in the logical volume lv01, so that a total of three copies exists for each logical partition, enter:

mklvcopy lv01 3

The logical partitions in the logical volume represented by directory lv01 have three copies.

Files

/usr/sbin/mklvcopy Contains the mklvcopy command.

Related Information

The chlv command, lslv command, mklv command, syncvg command, varyonvg command.

The Logical Volume Storage Overview in AIX Version 4.3 System Management Guide: Operating System and Devices.

Setting up and running Web-based System Management in AIX Version 4.3 System Management Guide: Operating System and Devices.

The System Management Interface Tool (SMIT): Overview in AIX Version 4.3 System Management Guide: Operating System and Devices.

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