Linux RHCSA Part 11 - LVM - Logical Volume Manager - Data Migration

Assuming you have an old and failing disk that needs to be replaced in the system, how can you move the data to a new one? In a system with standard partitions, you can copy all data from one disk to another, provided the disk is offline (otherwise, files might be locked). Working with LVM is much easier because you can migrate data while the disk is "online" without disrupting operations. This capability is very useful, especially when a disk replacement is necessary. So, if you need to replace the disk /dev/hdb because something happened to it, you can use the "pvmove" command to move data from its physical location—where the data actually resides—to another physical volume, e.g., /dev/hdc. 

Assuming we are adding a new disk and want to migrate the data, the entire process will follow these steps:

Step 1 - Check which physical volumes are inside the volume group

-- Logical volume --