pvmove Command - LVM Physical Volume Move Utility - cmd Cheatsheets

The pvmove command is a powerful utility within the Logical Volume Manager (LVM) suite in Linux. Its primary function is to move physical extents (PEs) from one physical volume (PV) to another. This is crucial for tasks such as rebalancing storage, migrating data to new disks, or freeing up space on a specific physical volume without interrupting service.

Understanding pvmove Operations

pvmove allows for flexible data migration. You can move all extents from a source PV to a destination PV, or selectively move extents associated with specific logical volumes. The command can also be used to redistribute data across available physical volumes in a volume group to optimize performance and utilization.

Key pvmove Command Examples

Here are some common use cases for the pvmove command:

Moving All Physical Extents

To move all physical extents from one physical volume (e.g., /dev/sdX) to another (e.g., /dev/sdY), you would use the following syntax:

pvmove /dev/sdX /dev/sdY

Moving Specific Logical Volumes

You can specify which logical volumes' extents to move. The --alloc anywhere option ensures that extents are allocated anywhere on the destination PV if the exact location is not specified. This example moves extents for a logical volume named vgname-lvname from /dev/sdX to /dev/sdY:

pvmove --alloc anywhere /dev/sdX:/dev/sdY /dev/mapper/vgname-lvname

Verbose Output for Monitoring

For detailed progress and information during the move operation, use the -v (verbose) flag:

pvmove -v /dev/sdX

Handling Uninitialized Physical Volumes

In scenarios where you might be dealing with physical volumes that have not been fully initialized or have skipped cluster configurations, you can use the --ignoreskippedcluster option:

pvmove --ignoreskippedcluster /dev/sdX /dev/sdY

Moving Extents from a Volume Group Device

You can also initiate a move operation for extents belonging to any device within a specific volume group to a designated device:

pvmove --alloc anywhere /dev/md0

Atomic Moves and Specific Ranges

The --atomic option ensures that the move operation is performed atomically, meaning it either completes successfully or is rolled back, preventing data corruption. You can also specify particular physical volume names and their corresponding physical extent ranges:

pvmove --atomic pvname[:pe_ranges] [destpv[:pe_ranges] [movedevice[:pe_ranges]]]

Aborting an In-Progress Operation

If you need to stop a pvmove operation that is currently running, you can use the --abort flag:

pvmove --abort

pvmove Command - LVM Physical Volume Move Utility