Reverse Cabling; Figure 20 Reverse Cabling - Fujitsu ETERNUS DX500 S4/DX600 S4 Design Manual

2. Basic Functions
Data Protection

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 20 Reverse Cabling

IOM#0
IOM#0
IOM#0
IOM#0
IOM#0
IOM#0
CM#0
(Connect the controller enclosure to the last drive enclosure)
Accessible
:
Inaccessible
:
FUJITSU Storage ETERNUS DX500 S4/DX600 S4, ETERNUS DX500 S3/DX600 S3 Hybrid Storage Systems Design Guide (Basic)
DE#05
IOM#1
DE#04
IOM#1
DE#03
IOM#1
DE#02
in a drive enclosure
IOM#1
DE#01
IOM#1
DE#00
IOM#1
CE
CM#1
Reverse cabling connection
Copyright 2019 FUJITSU LIMITED
A failure occurs
Continued access is available to drives
in the drive enclosures that follow the failed one.
41
DE#05
IOM#0 IOM#1
DE#04
IOM#0 IOM#1
DE#03
IOM#0 IOM#1
DE#02
Failure
IOM#0 IOM#1
DE#01
IOM#0 IOM#1
DE#00
IOM#0 IOM#1
CE
CM#0 CM#1
P3AM-7722-25ENZ0