If your Fibre Channel performance is poor
If your Fibre Channel fabric isn’t running at the expected speed (typically, 2 or 4 Gb/s, depending on your equipment), review the following information.
One faulty cable in a fabric can slow the entire network. Check all cables to make sure they’re capable of full transmission speed. Use your switch management software to isolate the faulty cable by checking the performance of specific connections.
Use qualified transceivers
Check with the manufacturers of the devices you’re connecting to your fabric to be sure that the transceivers (GBICs) you’re using are qualified for use with their devices.
With some Fibre Channel switches, you should use identical transceivers (same manufacturer and model number) on both ends of each cable. Mismatched optical transceivers (even if they’re separately qualified for use with your devices) can cause Fibre Channel communication errors and degrade SAN performance.
With Cisco Fibre Channel switches, you should use a Cisco transceiver on the end of a cable that plugs into the switch, but use another qualified transceiver at the other end of the cable.
For Fibre Channel hardware compatibility information, see Fibre Channel hardware compatibility guide.
Check Fibre Channel switch port configuration
The Request for State Change Notifications (RSCN) that’s generated when a client on the SAN restarts can cause dropped frames in video streams to other clients.
To avoid interrupting SAN traffic to other clients if one client restarts, check your Fibre Channel switch documentation to see if you can configure the switch to suppress RSCNs on initiator ports. (For example, on QLogic switches this feature is called I/O StreamGuard.)
Connect devices to specific blades
If your Fibre Channel switch is based on a blade architecture, try the following for best performance:
Connect pairs of devices that routinely exchange large volumes of data to the same blade in the switch
Distribute loads across multiple blades, instead of concentrating all of it on one or two blades