3PAR InForm® OS 2.3.1 Concepts Guide (320-200112 Rev B, February 2010)

12.7
Thin Persistence
InForm OS Version 2.3.1 3PAR InForm OS Concepts Guide
12.6 Thin Persistence
Thin Persistence is an optional feature that keeps InServ TPVVs small by detecting pages of
zeros during data transfers and not allocating space for the zeros. This feature works in real-
time and analyzes the data before it is written to the source TPVV. Freed blocks of 16 KB of
contiguous space are returned to the source volume, freed blocks of 128 MB of contiguous
space are returned to the CPG for use by other volumes.
To use Thin Persistence functions, you must have an InServ F-Class or T-Class Storage Server. The
3PAR Thin Persistence feature is automatically enabled on InServ F-Class and T-Class Storage
Servers. Thin Persistence tasks can be performed with both the 3PAR InForm Command Line
Interface (CLI) and the 3PAR InForm Management Console. Refer to the 3PAR InForm OS CLI
Administrator’s Manual and the 3PAR InForm Management Console Online Help for
instructions on how to perform these tasks.
NOTE: Converting fully-provisioned volumes to Thinly-Provisioned Virtual
Volumes (TPVVs) with the Thin Conversion feature requires an InServ F-Class or T-
Class Storage Server, a 3PAR Thin Provisioning license, and a 3PAR Thin Conversion
license. Contact your 3PAR representative for more information.
NOTE: Maintaining TPVV size with the 3PAR Thin Persistence feature requires an
InServ F-Class or T-Class Storage Server, a 3PAR Thin Provisioning license, a 3PAR
Thin Conversion license, and a 3PAR Thin Persistence license. Contact your 3PAR
representative for more information.