Table of Contents
Advertisement
cases when a single component fails, the Service Action Allowed status LED turns
on steadily when the Needs Attention status LED is turned on for the component.
Adding the EXP420 to an existing and configured redundant drive
channel/loop pair
Note: The term drive loop or drive loop pair used in this publication might be
You can add up to six EXP420s to a redundant fibre-channel loop pair. Before you
cable your EXP420 to a drive loop, refer to the Installation, User's and Maintenance
Guide or System Storage Quick Start Guide that came with your storage subsystem
for specific instructions.
Attention:
either 2 or 4 Gbps fibre channel interface speed. The EXP420 SATA EV-DDM
CRUs have an ATA translator card that converts EV-DDM 3 Gbps SATA drive
interface protocol to either 2 Gbps or 4 Gbps fibre channel interface protocol. It is
recommended that the EXP420 enclosure speed is set to 4 Gbps when these SATA
EV-DDM CRUs are installed and connected to storage expansion enclosures
running at 4 Gbps speed. The Link Rate setting speed must be set accordingly. See
"Verifying the Link Rate setting " on page 86 for more information. The enclosure
speed of the DS4200 Express Storage Subsystem that the EXP420s are connected
to must also be set to 4 Gbps.
Figure 43 on page 75 shows an example of a DS4000 storage subsystem
configured with redundant drive loop pairs.
74
IBM System Storage DS4000 EXP420 Storage Expansion Enclosure: Installation, User's and Maintenance Guide
referred to as a drive channel or drive channel pair in other DS4000 Storage
Subsystem publications. The terms have identical meanings.
The EXP420 storage expansion enclosure drive channel operates at
Attention
Before you power on the DS4200 Express Storage Subsystem, the DS4200
Express must be cabled to at least one storage expansion enclosure
populated with at least two drives. If at least two drives are not installed in
each attached storage expansion enclosure when you power on the DS4200
Express, your standard storage partition key will be lost and will need to be
regenerated using instructions on the IBM DS4000 Solutions and Premium
Features Web site:
https://www-912.ibm.com/PremiumFeatures/
Additionally, if at least two drives are not installed in each attached storage
expansion enclosure, the resulting insufficient load to the storage expansion
enclosure power supply CRUs might cause the drive expansion enclosure
power supply CRUs to intermittently appear as failed and then reappear in an
optimal state, falsely indicating that the power supply CRUs are bad.
Advertisement
Table of Contents
