HP Virtual Connect Fibre Channel Networking Scenarios Cookbook

16
Increased bandwidth
Depending on the VC Fibre Channel module and the number of uplinks used, the server-to-uplink ratio
(oversubscription ratio) is adjustable to 2:1, 4:1, 8:1, or 16:1. As few as two or as many as 16 servers share one
physical link on a fully populated enclosure with 16 servers.
Using multiple uplinks reduces the risk of congestion.
Figure 13: 2:1 oversubscription with 24-port VC-FC
modules
16 servers
8 Uplinks
2:1
VC-FC
24-port
Figure 14: 4:1 oversubscription with 20-port VC-
FC modules and with VC FlexFabric modules
16 servers
4 Uplinks
4:1
VC-FC
20-port
Dynamic Logins Load Balancing and increased redundancy
When VC Fabric uplinks are grouped into a single fabric, the module uses dynamic login distribution to load balance
the server connections across all available uplink ports.
The module uses the port with the least number of logins across the VC SAN Fabric or, when the number of logins is
equal, VC makes a round-robin decision.
VC version 3.0 and later do not offer Static Uplink Login Distribution.
Figure 15: Dynamic Logins Load Balancing with VC-FC module
VC Domain
VC-FC Module
Fabric 1
VC SAN 1
Server 1 Server 2 Server 3 Server 4
HBA1 HBA2
HBA1 HBA2 HBA1 HBA2
Server 3
Server 2
Server 1
HBA1 HBA2
Server 4