Changes only the characteristics of a logical volume.
To Change the Characteristics of a Logical Volume
chlv [ -a position ] [ -b badblocks ] [ -d schedule ] [ -e Range ] [ -L label ] [ -o y | n ] [ -p permission ] [ -r relocate ] [ -s strict ] [ -t type ] [ -u upperbound ] [ -v verify ] [ -w mirrorwriteconsistency ] [ -x maximum ] [ -T O | F ] [ -U userid ] [ -G groupid ] [ -P modes ] [ -m copyn=mirrorpool ] [ -M copyn ] [ -O { y | n }] logicalvolume ...
To Change the Name of a Logical Volume
The changes you make with the -a, -e, -s, and -u flags take effect only when new partitions are allocated or partitions are deleted. The other flags take effect immediately.
To change the name of a logical volume, use the -n flag and use the newlogicalvolume parameter to represent the new logical volume name. Do not use other flags with this syntax.
You can use the Volumes application in Web-based System Manager (wsm) to change logical volume characteristics. You could also use the System Management Interface Tool (SMIT) smit chlv fast path to run this command.
See the section "Administering a PowerHA® cluster" in the PowerHA SystemMirror Administration Guide, 7.1 or later, for a discussion of the behavior of this command in a PowerHA cluster.
Item | Description |
---|---|
-a position | Sets the intraphysical volume allocation policy (the position
of the logical partitions on the physical volume). The position variable is represented by one of the following:
|
-b badblocks | Sets the bad-block relocation policy. The badblocks variable
is represented by one of the following:
|
-d schedule | Sets the scheduling policy when more than one logical partition
is written. Must use parallel or sequential to mirror striped lv.
The schedule variable is represented by one of the following:
|
-e range | Sets the interphysical volume allocation policy (the number
of physical volumes to extend across, using the volumes that provide
the best allocation). The value of the range variable is limited
by the upperbound variable, set with the -u flag, and is represented
by one of the following:
|
-G groupid | Specifies group ID for the logical volume special file. |
-L label | Sets the logical volume label. The maximum size of the label variable is 127 characters. |
-m copyn=mirrorpool | Enables mirror pools to the copies of a logical volume. A mirror pool is assigned to a copy using the copyn=mirrorpool parameter. Specify a mirror pool for each copy of the logical volume. To specify more than one copyn=mirrorpool pair, provide multiple -m copyn=mirrorpool flags. |
-M copyn | Disables mirror pools on the specified copy for this logical volume. The copyn variable specifies which copy to disable mirror pools on. To disable mirror pools on more than one copy, provide multiple -M copyn flags. |
-n newlogicalvolume | Changes the name of the logical volume to that specified by the newlogicalvolume variable. Logical volume names must be unique system wide and can range from 1 to 15 characters. |
-o y | n | Turns on/off serialization of overlapping IOs. If serialization is turned on then overlapping IOs are not allowed on a block range, and only a single IO in a block range is processed at any one time. Most applications like file systems and databases do serialization, and hence serialization should be turned off. The default for new logical volumes is off. |
-O y | n | Changes the infinite retry option of the logical
volume.
Note:
|
-p permission | Sets the access permission to read-write or read-only. The permission variable is represented by one of the following:
Note: Mounting a JFS file system on a read-only logical
volume is not supported.
|
-P modes | Specifies permissions (file modes) for the logical volume special file. |
-r relocate | Sets the reorganization flag to allow or prevent the relocation
of the logical volume during reorganization. The relocate variable
is represented by one of the following:
|
-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 is represented by one of the following:
Note: When changing a non superstrict logical volume
to a superstrict logical volume you must use the -u flag.
|
-t type | Sets the logical volume type. The maximum size is 31 characters. If the logical volume is striped, you cannot change type to boot. |
-T O | F | For logical volumes in big and scalable volume groups, the -T flag changes the device subtype reported by the IOCINFO ioctl call. Use the -T O option for a subtype of DS_LVZ and the -T F option for a subtype of DS_LV. Tip: The -T flag does not change any behavior of a logical volume beyond the reported subtype. |
-U userid | Specifies user ID for the logical volume special file. |
-u upperbound | Sets the maximum number of physical volumes for new allocation. The value of the upperbound variable should be between one and the total number of physical volumes. When using super strictness, the upper bound indicates the maximum number of physical volumes allowed for each mirror copy. When using striped logical volumes, the upper bound must be multiple of stripewidth. |
-v verify | Sets the write-verify state for the logical volume. Causes
all writes to the logical volume either to be verified with a follow-up
read or not to be verified with a follow-up read. The verify variable is represented by one of the following:
|
-w mirrorwriteconsistency |
|
-x maximum | Sets the maximum number of logical partitions that can be allocated to the logical volume. |
Attention RBAC users and Trusted AIX® users: This command can perform privileged operations. Only privileged users can run privileged operations. For more information about authorizations and privileges, see Privileged Command Database in Security. For a list of privileges and the authorizations associated with this command, see the lssecattr command or the getcmdattr subcommand.
chlv -e m
lv01
The interphysical volume allocation policy is set
to minimum.chlv -t copy lv03
chlv -p r lv03
Logical volume lv03 now has read-only permission.chlv -t paging -u 10 lv03
The change
in the type of logical volume takes effect immediately, but the change
in the maximum number of physical volumes does not take effect until
a new allocation is made.chlv -a e -e x -r y -s n -u 5 lv07
Item | Description |
---|---|
/usr/sbin | Directory where chlv command resides. |