Fabric OS Administrator's Guide v7.0.0 (53-1002148-02, June 2011)

Fabric OS Administrator’s Guide 77
53-1002148-02
Lossless Dynamic Load Sharing on ports
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Forcing in-order frame delivery across topology changes
1. Connect to the switch and log in as admin.
2. Enter the iodSet command.
NOTE
The iodSet command can cause a delay in the establishment of a new path when a topology
change occurs; use it with care.
3. Confirm the in-order delivery has been set by entering the iodShow command.
Restoring out-of-order frame delivery across topology changes
1. Connect to the switch and log in as admin.
2. Enter the iodReset command.
Lossless Dynamic Load Sharing on ports
Lossless Dynamic Load Sharing (DLS) allows you to rebalance port paths without causing
input/output (I/O) failures. For devices where in-order delivery (IOD) of frames is required, you can
set IOD separately. You can use this feature with the following hardware:
• Brocade 300
• Brocade 5100
• Brocade 5300
• Brocade 6510
• Brocade VA-40FC switches
• Brocade FC8-16, FC8-32, FC8-48, and FC8-64 port blades,
• Brocade DCX 8510-8
• Brocade 6510-4 and the supported blades.
• Brocade FC16-32 and FC16-48
• Brocade FX8-18 application blades in the Brocade DCX and DCX-4S enterprise-class platforms.
On the Brocade 7800 switch and the FX8-24 application blade, Lossless DLS is supported only on
FC-to-FC port flows.
ATTENTION
When you implement Lossless DLS, the switches in the fabric must all have either Fabric OS v6.3.0
or they must all have Fabric OS v6.4.0 or later installed to guarantee no frame loss.
Lossless DLS must be implemented along the path between the target and initiator. You can use
Lossless DLS on ports connecting switches to perform the following functions:
• Eliminate dropped frames and I/O failures by rebalancing the paths going over the ISLs
whenever there is a fabric event that might result in suboptimal utilization of the ISLs.
• Eliminate the frame delay caused by establishing a new path when a topology change occurs.