HP XP P9500 Storage - Manual (Page 14)

The alternative is to use a host-based Logical Volume Manager (LVM) when the planned workloads
require either more space or IOPS capacity than the individual physical volumes can provide. LVM
is the disk management feature available on UNIX-based operating systems, including Linux, that
manages their logical volumes.
The following illustrates a fixed-size provisioning environment using LUNs in host-managed logical
volumes:
In either case, hosts recognize the size as fixed regardless of the actual used size. Therefore, it is
not necessary to expand the volume (LDEV) size in the future if the actual used size does not exceed
the fixed size.
When such a logical volume runs out of space or IOPS capacity, you can replace it with one that
was created with even more physical volumes and then copy over all of the user data. In some
cases, it is best to add a second logical volume and then manually relocate just part of the existing
data to redistribute the workload across two such volumes. These two logical volumes would be
mapped to the server using separate host paths.
14 Introduction to provisioning