Apple Xsan 1.x - Manual (Page 9)

Chapter 1 Setup and Tuning Guidelines 9
Use Qualified Transceivers in Matching Pairs
Check with the manufacturers of the devices you are connecting to your fabric to be
sure that the transceivers (GBICs) you are using are qualified for use with their devices.
Also, use identical transceivers (same manufacturer and model number) on both ends
of each cable. Mismatched optical transceivers (even if they are both separately
qualified for use with your devices) can cause Fibre Channel communication errors and
degrade SAN performance.
Check Fibre Channel Switch Port Configuration
The Request for State Change Notifications (RSCN) that is 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. (On Qlogic switches, for example, this feature is called I/O
StreamGuard.)
Connect Devices to Specific Blades
If your Fibre Channel switch is based on a blade architecture, you might be able to
improve performance by:
 Connecting pairs of devices that routinely exchange large volumes of data to the
same blade in the switch
 Distributing loads across multiple blades instead of concentrating all of the load on
one or two blades
Configuring Xserve RAID Systems
Follow these guidelines when you set up your Xserve RAID systems for use as Xsan
LUNs.
Install the Latest Firmware
To be sure you get the best performance and reliability from your Xserve RAID systems,
be sure to install the latest available firmware.
To check for firmware updates:
m Visit www.apple.com/support/xserve/raid/
Connecting Xserve RAID Systems to an Ethernet Network
For best performance, don’t connect Xserve RAID controller Ethernet management
ports to the SAN’s metadata network. Connect the ports to a separate Ethernet
network.