IBM DS6000 Series Configuring multipath, Figure B-23 Multipath removes single points of failure

Figure B-23 Multipath removes single points of failure

Unlike other systems, which may only support two paths (dual-path), OS/400 V5R3 supports up to eight paths to the same logical volumes. As a minimum, you should use two, although some small performance benefits may be experienced with more. However, since OS/400

multipath spreads I/O across all available paths in a round-robinmanner, there is no load balancing, only load sharing.

Configuring multipath

iSeries has two I/O adapters that support DS6000:

￿2766 2 Gigabit Fibre Channel Disk Controller PCI

￿2787 2 Gigabit Fibre Channel Disk Controller PCI-X

Both can be used for multipath and there is no requirement for all paths to use the same type of adapter. Both adapters can address up to 32 logical volumes. This does not change with multipath support. When deciding how many I/O adapters to use, your first priority should be to consider performance throughput of the IOA since this limit may be reached before the maximum number of logical units. See “Sizing guidelines” on page 353 for more information on sizing and performance guidelines.

344DS6000 Series: Concepts and Architecture