Reverse Cabling; Figure 19 Reverse Cabling - Fujitsu ETERNUS DX60 S4 Design Manual

1. Function
Data Protection
The target drives are deactivated and then reactivated during temporary drive protection. Even though a
•
system status error may be displayed during this period, this phenomenon is only temporary. The status
returns to normal after the diagnosis is complete.
The following phenomenon may occur during temporary drive protection.
The Fault LEDs (amber) on the operation panel and the drive turn on
-
- An error status is displayed by the ETERNUS Web GUI and the ETERNUS CLI
Error or Warning is displayed as the system status
•
Error, Warning, or Maintenance is displayed as the system status
•
Target drives of the Protection (Shield) function only need to be replaced when drive reactivation fails.
•
If drive reactivation fails, a drive failure error is notified as an event notification message (such as SNMP/
REMCS). When drive reactivation is successful, an error message is not notified. To notify this message, use
the event notification settings.
To set the Protection (Shield) function for each storage system, use the subsystem parameter settings. The
•
maintenance operation privilege is required to perform this setting.
After the settings are changed, the ETERNUS DX does not need to be turned off and on again.

Reverse Cabling

Because the ETERNUS DX uses reverse cabling connections for data transfer paths between controllers and
drives, continued access is ensured even if a failure occurs in a drive enclosure.
If a drive enclosure fails for any reason, access to drives that are connected after the failed drive can be main-
tained because normal access paths are secured by using reverse cabling.

Figure 19 Reverse Cabling

IOM#0
IOM#0
IOM#0
CM#0
(Connect the controller enclosure to the last drive enclosure)
Accessible
:
Inaccessible
:
FUJITSU Storage ETERNUS DX60 S4, ETERNUS DX60 S3 Hybrid Storage Systems Design Guide (Basic)
DE#03
IOM#1
DE#02
in a drive enclosure
IOM#1
DE#01
IOM#1
CE
CM#1
Reverse cabling connection
Copyright 2019 FUJITSU LIMITED
A failure occurs
Continued access is available to drives
in the drive enclosure that follows the failed one.
35
DE#03
IOM#0 IOM#1
DE#02
IOM#0 Failure IOM#1
DE#01
IOM#0 IOM#1
CE
CM#0 CM#1
P3AM-8992-14ENZ0