Load Assignment On World Wide Node Names - EMC Connectrix EC-1200 Planning Manual

Load Assignment on
World Wide Node
Names
Figure 2-7
EC-1200-based directors and switches offer a unique load assignment
algorithm. When configuring a fabric with a server that uses EMC
PowerPath™, it is best to split the server's links across fabrics. In
some cases, however, multiple HBAs from a server may enter a fabric
through the same domain.
To insure that the load balancing services provided by PowerPath are
effective over the ISLs, a load-balancing algorithm based on World
Wide Node Names is employed. If the HBA applies a common
WWNN to all the HBAs in the server, and there are multiple ISLs of
equal cost, the EC-1200 product will spread the ISL assignment over
the set of ISLs.
In Figure 2-7, the fabric will route the frames from one HBA over a
different ISL than the frames from the other HBA. This function
depends on support in the device driver for a common WWNN. As
of the current revision of this Planning Guide, this support is
provided by the Emulex Windows NT driver, and is in development
for the UNIX device drivers.
Server
with
PowerPath
Connectrix
HBA
Domain ID 1
HBA
Load Balancing
Fibre Channel Switching Concepts
Symmetrix
Connectrix
Domain ID 2
Path Selection and ISL Loading
2
2-23