Rebuild/Copyback; Figure 5.4 Rebuild/Copyback Function - Fujitsu ETERNUS DX80 S2 Overview

Chapter 5 Basic Functions
5.1 Data Protection
5.1.4

Rebuild/Copyback

When a drive fails and RAID group redundancy is broken, Rebuild/Copyback restores the drive status back to
normal status as a background process. If a free hot spare is available when one of the RAID group drives has
a problem, data of this drive is automatically replicated in the hot spare. This ensures data redundancy.

Figure 5.4 Rebuild/Copyback function

RAID5 (No Redundancy)
RAID5 (Redundant)
RAID5 (Redundant)
RAID5 (Redundant)
Failure
Replaces the failed drive with the new drive.
Copyback
51
ETERNUS DX80 S2/DX90 S2 Disk storage system Overview
Copyright 2013 FUJITSU LIMITED
Rebuild
Creates data from the drives other than
the failed drive and writes the data into
the hot spare.
Hot spare
After replacing has been completed,
copies the data from the hot spare
to the new drive.
Hot spare
P3AM-4812-11ENZ0