Logical volume; Physical volume
The storage provided by a storage device is offered in the form of volumes. A volume corresponds to a logically contiguous piece of storage. The volumes offered by storage devices are typically known as physical volumes.
Storage controllers usually create volumes by stripping them across multiple disks that belong to a RAID group. RAID 1 (mirroring), RAID 5 (use of parity, but no dedicated parity disk), and RAID 6 (can tolerate two failures) are the most common RAID types. These volumes get mapped into LUNs by host OS, or aggregated into logical volumes by a logical volume manager, or aggregated into virtual volumes by virtualization software. A file system and its associated files ultimately reside in a physical volume on a storage device. Database table’s data also ultimately resides in a physical volume on a storage device. Storage vendors typically use Volume as the unit of management. That is, they allow volume level...