HP Virtual Connect Fibre Channel Networking Scenarios Cookbook

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Figure 59: Newly distributed logins
VC Domain
Fabric-1
Fabric-2
Server 1
HBA1
HBA2
Server 2
HBA1
HBA2
Server 3
HBA1
HBA2
VC-FC 8Gb
20-port Module
Fabric 1
Fabric 2
Server 2
Server11
Server 1
Server 3
Server 7
Summary
This scenario demonstrates how to add an uplink port to an existing VC-FC fabric with Dynamic Login Balancing
enabled. VCM allows you to manually redistribute the HBA host logins to balance the FC traffic through a newly
added uplink port. New logins go to the newly added port until the number of logins becomes equal. After this, the
login distribution uses a round robin method of assigning new host logins.
Logins are not redistributed if you do not use this manual method, with one exception. With the Virtual connect
FlexFabric module, automatic login redistribution is available by configuring a link stability interval parameter. This
interval defines the number of seconds that the VC module waits for the VC Fabric uplinks to stabilize before the
module attempts to re-load balance the server logins.
Login redistribution can affect the server traffic because the hosts must re-login before resuming their I/O
operations. A smooth transition without much traffic disruption can occur with a redundant Fabric connection and an
appropriate server MPIO driver.