IBM PureFlex System and IBM Flex System Products and Technology

288 IBM PureFlex System and IBM Flex System Products and Technology

If you plan to use redundancy and high availability for storage fabric, ensure that failover

drivers satisfy the following requirements:

򐂰 They are available from the vendor of the storage system.

򐂰 They come with the system or can be ordered separately (remember to order them in such

cases).

򐂰 They support the node operating system.

򐂰 They support the redundant multipath fabric that you plan to implement (that is, they

support the required number of redundant paths).

For more information, see the storage system documentation from the vendor.

7.5 Performance

Performance is an important consideration during storage infrastructure planning. Providing

the required end-to-end performance for your SAN can be accomplished in several ways.

First, the storage system’s failover driver can provide load balancing across redundant paths

in addition to high availability. IBM System Storage Multi-path Subsystem Device Driver

(SDD) used with DS8000 provides this function. If you plan to use such drivers, ensure that

they satisfy the following requirements:

򐂰 They are available from the storage system vendor.

򐂰 They come with the system, or can be ordered separately.

򐂰 They support the node operating system.

򐂰 They support the multipath fabric that you plan to implement. That is, they support the

required number of paths implemented.

Also, you can use static LUN distribution between two storage controllers in the storage

system. Some LUNs are served by controller 1, and others are served by controller 2. A

zoning technique can also be used together with static LUN distribution if you have redundant

connections between FC switches and the storage system controllers.

Trunking or PortChannels between FC or Ethernet switches can be used to increase network

bandwidth, increasing performance. Trunks in the FC network use the same concept as in

standard Ethernet networks. Several physical links between switches are grouped into one

logical link with increased bandwidth. This configuration is typically used when an Enterprise

Chassis is integrated into existing advanced FC infrastructures. However, keep in mind that

only the FC5022 16Gb SAN Scalable Switch supports trunking. Also be aware that this is an

optional feature that requires the purchase of an additional license.

For more information, see the storage system vendor documentation and the switch vendor

documentation.