Overview - IBM N Series Hardware Manual

The EXN3500 SAS expansion unit is a 2U SFF disk storage expansion unit that must be
mounted in an industry standard 19-inch rack. It can be attached to all N series systems
except N3300, N3700, N5200, and N5500. It includes the following features:
Third-generation SAS product
Increased density
24x2.5" 10k RPM drives in 2 rack U at same capacity points (450 GB, 600 GB) offers
double the GB/rack U of the EXN3000
Increased IOPs/rack U
Greater bandwidth
6 Gb SAS 2.0 offers ~24 Gb (6 Gb x4) combined bandwidth per wide port
Improved power consumption: Power consumption per GB reduced by approximately
30-50%*
Only SAS drives are supported in the EXN3500: SATA is not supported
What has not changed:
Same underlying architecture and FW base as EXN3000
All existing EXN3000 features/functionality
Still use the 3 Gb PCIe Quad-Port SAS HBA (already 6 Gb capable) or onboard SAS ports

5.3.1 Overview

The EXN3500 includes the following hardware:
Dual, redundant, hot-pluggable, integrated power supplies and cooling fans
Dual, redundant, disk expansion unit switched controllers
24 SFF hard disk drive slots
Diagnostic and status LEDs
Figure 5-4 shows the EXN3500 front view.
Figure 5-4 EXN3500 front view
The EXN3500 SAS expansion unit can be shipped with no disk drives installed. Disk drives
ordered with the EXN3500 are installed by IBM in the plant before shipping. Disk drives can
be of 450 GB and 600 GB physical capacity, and must be ordered as features of the
EXN3500.
Requirement: For an initial order of an N series system, at least one of the storage
expansion units must be ordered with at least five disk drive features.
Chapter 5. Expansion units
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