HP StorageWorks Fabric OS 6.x administrator guide (5697-0015, May 2009)

368 Administering Extended Fabrics
NOTE: Additional buffers are available with 4Gbps chassis for 8Gbps blades because of fewer buffers
allocated for back-end port connections.
Fabric considerations
Because the number of buffer credits available for use within each port group is limited, configuring buffer
credits for extended links may impact the performance of the other ports in the group used for core-to-edge
connections. Balance the number of long-distance ISL connections and core-to-edge ISL connections within
a switch. Configuring long-distance ISLs between core and edge switches is possible, but is not a
recommended practice.
With the exception of older switches and blades that use the Bloom ASIC, all switch ports provide
protection against buffer depletion through buffer limiting. A buffer-limited port reserves a minimum of
eight buffer credits, allowing the port to continue to operate rather than being disabled due to a lack of
buffers. The 8 buffer minimum allows 4 Gbps speeds over distances within most data centers.
Buffer-limited operation is supported for the L0 and LD extended ISL modes only, and is persistent across
reboots, switch disabling and enabling, and port disabling and enabling.
Table 81 Switch, port speed, and distance with ASIC and buffers
Switch blade
model
ASIC Total ports in
a switch or
blade
Total ports in a
group
Reserved
buffers for ports
4/8 SAN Switch
or 4/16 SAN
Switch
Golden Eye 16 272/16 8
SAN Switch
4/32 and SAN
Switch 4/32B
Condor 32 1000/32 8
4/64 SAN
Switch
Condor 64 712/16 8
400
Multi-protocol
(MP) Router
Condor 16 441/8 8
FR4-18i Condor 16 441/8 8
FC4-16iP Condor 8 680/8 8
F C4 -16 C on do r 16 712 /16 8
FC4-32 Condor 32 752/16 8
FC4-48 Condor 48 752/24 8
FC10-6 Egret and Condor 6 712/1 N/A
FC8-16 Condor2 16 1420/16
*1516/16
8
FC8-32 Condor2 32 1420/16
*1516/16
8
FC8-48 Condor2 48 1420/24
*1516/24
8