Answer in Short
Explanation
Virtual Storage Provisioning
➢ Virtual provisioning enables creating and presenting a LUN with more capacity than
is physically allocated to it on the storage array.
➢ The LUN created using virtual provisioning is called a thin LUN to distinguish it
from the traditional LUN.
➢ Thin LUNs do not require physical storage to be completely allocated to them at the
time they are created and presented to a host.
➢ Physical storage is allocated to the host “on-demand” from a shared pool of physical
capacity.
➢ A shared pool consists of physical disks.
➢ A shared pool in virtual provisioning is analogous to a RAID group, which is a
collection of drives on which LUNs are created.
➢ Similar to a RAID group, a shared pool supports a single RAID protection level.
However, unlike a RAID group, a shared pool might contain large numbers of drives.
➢ Shared pools can be homogeneous (containing a single drive type) or heterogeneous
(containing mixed drive types, such as flash, FC, SAS, and SATA drives).
➢ Virtual provisioning enables more efficient allocation of storage to hosts.
➢ Virtual provisioning also enables oversubscription, where more capacity is presented
to the hosts than is actually available on the storage array.
➢ Both shared pool and thin LUN can be expanded non-disruptively as the storage
requirements of the hosts grow.
➢ Multiple shared pools can be created within a storage array, and a shared pool may be
shared by multiple thin LUNs.
