Attention:
The EXP395 storage expansion enclosure drive channel operates at 4
Gbps fibre channel interface speed. The EXP395 SATA E-DDM FRUs have an ATA
translator card that converts E-DDM 3 Gbps SATA drive interface protocol to 4
Gbps fibre channel interface protocol. It is recommended that the EXP395 enclosure
speed is set to 4 Gbps when these SATA E-DDM FRUs are installed and connected
to storage expansion enclosures running at 4 Gbps speed. The Link Rate setting
speed must be set accordingly. The enclosure speed of the DS3950 storage
subsystem that the EXP395s are connected to must also be set to 4 Gbps.
Attention
Before you power on a DS3950 storage subsystem without any internal drive
slots, the DS3950 must be cabled to at least one storage expansion enclosure
populated with at least two E-DDMs. If at least two E-DDMs are not installed
in each attached storage expansion enclosure when you power on the DS3950
storage subsystem, your standard storage partition key will be lost and will
need to be regenerated using instructions on the IBM Solutions and Premium
Features Web site:
https://www-912.ibm.com/PremiumFeatures/
Additionally, if at least two E-DDMs are not installed in each attached storage
expansion enclosure, the resulting insufficient load to the storage expansion
enclosure power supply FRUs might cause the storage expansion enclosure
power supply FRUs to intermittently appear as failed and then reappear in
an optimal state, falsely indicating that the power supply FRUs are bad.
Figure 33 on page 67 shows an example of a DS3950 storage subsystem configured
with redundant drive loop pairs.
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IBM System Storage DS3950 EXP395 Storage Expansion Enclosure: Installation, User’s, and Maintenance Guide
Summary of Contents for DS3950
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