Rebuild/Copyback; Figure 8 Rebuild/Copyback Function - Fujitsu ETERNUS DX500 S3 Overview

3. Basic Functions
Data Protection

Rebuild/Copyback

When a drive fails and RAID group redundancy is broken, Rebuild/Copyback restores the drive status back to nor-
mal 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.
Copyback can be performed automatically by changing the copyback setting. Copyback is not automatically per-
formed by default when a failed drive is replaced and the replacement drive is used as a hot spare (Copyback-
less).

Figure 8 Rebuild/Copyback Function

RAID5 (No redundancy)
RAID5 (Redundant)
RAID5 (Redundant)
RAID5 (Redundant)
Failure
Replaces the failed drive with the new drive.
Copyback
31
FUJITSU Storage ETERNUS DX500 S3/DX600 S3 Hybrid Storage Systems Overview
Copyright 2019 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-7702-29ENZ0