Sas Attachment - IBM System Storage DS3500 Introduction And Implementation Manual

Draft Document for Review March 28, 2011 12:24 pm
Figure 4-21 An example of a multi-host, multi-port and multi-fabric host configuration
Before you attach hosts to the storage subsystem, you should always ensure that the host
systems and host bus adapters (HBAs) are installed correctly and updated with the supported
firmware and drivers levels. The supported levels are documented in the readme files that
come with the version of DS3500 firmware and DS Storage Manager that you want to use.

4.8.1 SAS attachment

Host server SAS HBAs are used to connect to the DS3500 SAS ports. Each DS3500
controller can have up to four SAS host ports when you install the optional SAS host interface
adapter. When the optional SAS host interface adapter is installed, the DS3500 can support
up to 28 Blade Center hosts when attached to the SAS Connectivity Module for IBM Blade
Center and up to four hosts in a direct attached host environment.
We recommend that you always use redundant host connections. The use of redundant host
connections with a single controller DS3500 storage subsystem is supported but limits the
number of hosts to a maximum of two if the optional SAS host card is installed in the DS3500.
SAS host attachment examples
In this section we show some examples of SAS host attachment with single and dual
controller DS3500 storage subsystems.
Figure 4-22 on page 112 shows the simplest host attachment method which is a single host
server with one SAS host bus adapter connecting to a single controller DS3500 storage
subsystem.
Best practise: Although the example shown in Figure 4-22 on page 112 is a valid
supported configuration, there is no redundancy of host side connections. Best practise is
to always use redundant host side connections.
Chapter 4. IBM System Storage DS3500 and EXP3500 Cabling
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