pvmove - Moves / Migrates Data from one physical volume to another
mearsure layers
two units
Physical Extents
Physical Extents are used dealing with volume groups and logical groups
logical extents
deal with logical extents
Raid
Striping disks together to form one large disk
Raid 1
Mirroring disks are copied from one another allowing for redundancy, should one disk fail the other one take sover.
Raid 5
Striping with Parity disks are similar to Raid 0 and are join together to form one large drive, the difference here is that 25% of the disk is used for parity bit.