3PAR InForm® OS 2.2.4 Concepts Guide (320-200085 Rev B, March 2009)

InForm OS Version 2.2.4 3PAR InForm OS Concepts Guide
A.1
Sparing
A
Sparing
In this appendix
A.1 Overview A.1
A.2 Viewing Spare Chunklets A.2
A.3 Creating Spare Chunklets A.4
A.4 Removing Spare Chunklets A.4
A.1 Overview
Some chunklets are identified as spares when the storage server is first set up at installation.
Data from other chunklets is moved or reconstructed onto these spare chunklets in response to
a chunklet or disk failure or when a drive magazine needs to be serviced, with the exception of
very small systems. This initial spare storage totals the amount of storage in a single drive
magazine (using the largest size physical disks).
Sparing works as follows:
■ When a connection is lost to a physical disk or a physical disk fails, all future writes to the
disk are automatically written to a logging logical disk until the physical disk comes back
online or until the time limit for logging is reached. (Logging disk space is allocated when
the storage server is set up. To set up additional logging logical disks, see the
createspare command in the InForm OS Command Line Interface Reference.)