Disk Patrol; Figure 5.2 Disk Check - Fujitsu ETERNUS DX80 S2 Overview

Chapter 5 Basic Functions
5.1 Data Protection
5.1.2

Disk Patrol

The Disk Patrol function regularly diagnoses and monitors the operational status of all disks that are installed
in the ETERNUS DX Disk storage system. Disks are checked (read check) regularly as a background process.
For disk checking, read check is performed sequentially for a part of the data in all the disks. If an error is
detected, data is restored using disks in the RAID group and the data is written back to another block of the
disk in which the error occurred.

Figure 5.2 Disk check

Data is read and
checked.
The data is written back
to another block.
Disks that are stopped by Eco-mode are checked when the disks start running again.
Error
detection
Error
D1
RAID group
D1
D1
D2 D3
D1
RAID group
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ETERNUS DX80 S2/DX90 S2 Disk storage system Overview
Copyright 2013 FUJITSU LIMITED
Data
reconstruction
P
D1 to D3: Data
P: Parity
P3AM-4812-11ENZ0