HP StorageWorks 8/80 HP StorageWorks Fabric OS 6.1.x administrator guide (5697 - Page 362

Setting port speeds For long-distance ports, if a port is set to autonegotiate port speed, the maximum speed (which is 8 Gbps) is assumed for reserving buffers for the port. If the port is only running at 2 Gbps this wastes buffers. For long-distance ports, it is best to set the port speed (this applies to the 4/32 SAN Switch, 4/32B SAN Switch and the 4/256 SAN Director only). On the HP StorageWorks 4/8 SAN Switch, 4/16 SAN Switch, 8/8 SAN Switch, 8/24 SAN Switch, SAN Switch 4/32, 4/256 SAN Director, 4/64 SAN Switch, DC Director, 8/40 SAN Switch, and 8/80 SAN Switch platforms, for long-distance ports, you should specify the port speed instead of setting it to autonegotiate. IMPORTANT: Support for 8 Gbps is only between the HP StorageWorks 4/256 SAN Director to the DC Director enterprise-class platform or between HP StorageWorks DC Director-to-DC Director enterprise-class platforms with the appropriate blades, the 8/8 SAN Switch, 8/24 SAN Switch, 8/40 SAN Switch, and 8/80 SAN Switch, and the 8 Gbps supported SFPs installed. The 8/8 SAN Switch, 8/24 SAN Switch, 8/40 SAN Switch, and 8/80 SAN Switch support long-distance modes L0, LE, LS, and LD. The distance supported on each platform depends on the available buffers, number of back-end ports, and number of offline ports. Table 79 Long-distance mode definitions Long-distance mode Distance L0 Normal LE Up to 10Km LS Static LD Auto distance detect Comments Normal mode. More than one data Virtual Channel is used. All other modes use one data Virtual Channel. Reserves the buffers for 10 km The distance statically specified by you. Reserves buffers for distance specified in the CLI. Fabric OS 6.1.x supports up to 500 km at 1G up to 250 km at 2G, and 100 km at 4G and 8G. You can set the port speed for one port or for an entire switch. Trunked ports must be set to the same speed. To set the speed for one port: 1. Connect to the switch and log in as admin. 2. Enter the portCfgSpeed command. The format is: 362 Administering ISL Trunking