IBM DS3500

installed on the RAID controller. To protect against the loss of any one path from
the host servers to the DS3500 storage subsystem, use redundant host
connections.
Notes:
1. In a single-controller storage subsystem, the use of redundant host connections
is supported. Redundant host connections provide path failover but limit the
number of redundant host connections to one.
2. The DS3500 ships with four storage partitions by default. For additional storage
partitions, purchase an optional Storage Partition Premium Feature upgrade.
Contact your IBM reseller or marketing representative for more information.
To connect a SAS host bus adapter (HBA) to the storage subsystem, complete the
following steps:
1. Connect a SAS cable from the RAID controller host port to the SAS HBA that is
in the host. Figure 16 on page 24 shows the location of the host ports.
2. Create a redundant host connection:
v If the storage subsystem is a single-controller storage subsystem, connect a
SAS cable from the second SAS HBA to another host port on the RAID
controller. You can create a maximum of one redundant host connection to a
single-controller storage subsystem.
v If the storage subsystem is a dual-controller storage subsystem, connect a
SAS cable from the second SAS HBA to a host port on the other RAID
controller. You can create a maximum of three redundant host connections to
a dual-controller storage subsystem.
See “Direct-attached single-controller connections” and “Direct-attached
dual-controller connections” on page 52 for illustrations of host connections.
Direct-attached single-controller connections: The following illustration shows a
direct-attached SAS connection to a single host HBA.
50 System Storage DS3500 and EXP3500: Installation, User’s, and Maintenance Guide