HP StorageWorks Enterprise File Services WAN Accelerator Deployment Guide (November 2005)

HP EFS WAN ACCELERATOR DEPLOYMENT GUIDE 19
1 - DESIGNING AN HP EFS
WAN A
CCELERATOR
In an out-of-path deployment, if the HP EFS WAN Accelerator fails, the first
connection from the client fails. After detecting that the HP EFS WAN
Accelerator is down, an HP EFS WAN Accelerator-ping channel is setup from
the client-side HP EFS WAN Accelerator to the server-side HP EFS WAN
Accelerator. Subsequent connections are passed through unoptimized. When
the HP EFS WAN Accelerator-ping succeeds, processing is restored and
subsequent connections are intercepted and optimized. For detailed
information about the HP EFS WAN Accelerator-ping command, see the HP
Enterprise File Services WAN Accelerator Command-Line Interface Reference
Manual.
Failover Mode
You can deploy redundant HP EFS WAN Accelerators in your network to
ensure optimization continues if there is a failure in one of the HP EFS WAN
Accelerators. If the HP EFS WAN Accelerator is in failover mode:
 optimization is lost on the current connections on the master HP EFS
WAN Accelerator.
 the backup HP EFS WAN Accelerator takes over and all new connections
are optimized.
 when the master HP EFS WAN Accelerator comes back up, the backup
HP EFS WAN Accelerator stops optimizing connections.