Move an NSS pool from one location to another on the same system. If the new location is larger than the original location, the pool is automatically expanded after the move is complete.
nlvm [nlvm_options] move <pool_name> <device> <size> [<device> <size>...]
You can use the device and size combination multiple times to create a move target comprised of multiple segments. You must specify a size for each device. The device and size options can be used in any order. The first device instance is matched to the first size instance, and so on. The move target’s size is the sum of the space contributed from the specified segments.
The total size of the target must be at least as big as the pool. You cannot shrink a pool by using the move command. If the size is larger, the pool size is expanded when the move is complete.
If a pool is cluster-enabled, issue the command on the node where the pool cluster resource is currently online. The move advances only when the resource is online. If the pool cluster resource is cluster migrated to another node, the move is enabled and active on the new node when the resource is brought online, and then the pool move continues. The status of the pool move can be reported only on the node where the resource is online.
The move command uses NSS software RAID mirroring underneath to copy the data to the target location. If server performance is too slow during a move, you can temporarily pause the mirroring with the nlvm pause move command. While the move is paused, the pool move status is reported as Not Enabled. Resume the mirroring with the nlvm resume move command. The pool move continues from where it was paused. The move will automatically resume in a cluster setup under certain conditions. See the nlvm resume move command for details.
You can check the status of a pool move by using the nlvm list move command.
When the move status is 100% complete, it is not yet final. You can issue the nlvm complete move <move_name> command to finalize the move. This sets the pool to the new location and removes the original location. Other NSS utilities might also complete the move. For information, see Moving a Pool
in the OES 2023: NSS File System Administration Guide for Linux.
You can delete a pool move by using the nlvm delete move command with the abort option. This sets the pool back to the original location and removes the new location.
In a cluster, issue the commands to complete, delete, or list the pool move from the node where the pool cluster resource is currently online.
Command Options
Mandatory. Specify the name of the NSS pool to be moved. This must be the first command option.
Example
MYPOOL1
Mandatory. Specify the target device where the pool will be relocated.
You can specify multiple device instances to create a move target comprised of multiple segments. Each device instance must have a matching size instance. The first device instance is matched to the first size instance, and so on.
Example
device=sdg
Mandatory. Specify the size of the target partition. The size must be the same size or larger than the source pool.
If multiple devices are specified, each device instance must have a matching size instance. The first size instance is matched to the first device instance, and so on.
Example
size=200G size=3.98T
Command Examples
Move the NSS pool named MYPOOL1 to the /dev/sdg device and allocate 200 GB to the partition.
Move the NSS pool named MYPOOL1 to a 700 GB space comprised of 200 GB of free space from device sdg and 500 GB of free space from device sdh.