Seagate ST336854FC, ST3146954FC manual Dual port support, Fibre Channel Arbitrated Loop options

9.1.10Fibre Channel Arbitrated Loop options

Table 15 lists the FC-AL options supported by Cheetah 15K.4 FC drives.

Table 15:	FC-AL options supported
Option		Supported
OPEN Half Duplex		Accepted from another device.
OPEN Full Duplex		Sent to open another device. Accepted from another device.
Private Loop		Yes
Public Loop		Yes
Old Port State		No
Loop Position		Yes
Loop Position Report		Yes

9.2Dual port support

Cheetah 15K.4 FC drives have two independent FC-AL ports. These ports may be connected on independent loops or on the same loop. Port A and Port B may be connected in any order or combination.

•If both ports are connected on independent loops and hard addressing is used, the drive interface address is selected through the interface connector, both ports will seek the same loop address. If no conflict, both ports will have the same loop address.

•If both ports are connected in the same loop and hard addressing is used, at least one port will attempt tak- ing a soft address to prevent an address conflict.

Note. When a Cheetah 15K.4 FC drive is connected in loops with previous Seagate FC drive products:

Barracuda 4LP FC (ST32171FC, ST34371FC, and ST34571FC) Barracuda 9FC (ST19171FC)

Cheetah 4LP FC (ST34501FC) Cheetah 9FC (ST19101FC)

the connection of Port A and B for these products must follow the requirements in their product manu- als.

Subject to buffer availability, the Cheetah 15K.4 FC drives support:

•Concurrent port transfers—The drive supports receiving transfers on both ports at the same time when the ports are on independent loops.

•Full duplex—The drive supports sending FCP_Data, FCP_RSP, FCP_XFR_RDY and ELS transfers while receiving frames on both ports.

Cheetah 15K.4 FC Product Manual, Rev. B 53