HP StorageWorks Enterprise File Services WAN Accelerator 2.1.5 deployment guide (June 2006)

14 1 - DESIGNING AN HP EFS WAN ACCELERATOR DEPLOYMENT
For detailed information about bypass card status lights, see the HP StorageWorks
Enterprise File Services WAN Accelerator Bypass NIC Installation Guide.
If there is a serious problem with the HP EFS WAN Accelerator or it is not powered
on, it goes into bypass mode to prevent a single point of failure. If the HP EFS WAN
Accelerator is in bypass mode, you are notified in the following ways:
 The Intercept/Bypass status light is active. For detailed information about the
status lights for each of the bypass cards, see the HP StorageWorks Enterprise
File Services WAN Accelerator Bypass NIC Installation Guide.
 Critical is displayed in the status bar of the Management Console.
 Simple Network Management Protocol (SNMP) traps are sent (if you have set
this option).
 The event is logged to system logs (syslog) (if you have set this option).
 Email notifications are sent (if you have set this option).
In an HP EFS WAN Accelerator in-path configuration, in the case of a failure, the
appliance automatically switches to bypass mode. Traffic that was passed-through is
uninterrupted. Traffic that was optimized might be interrupted, depending on the
behavior of the application-layer protocols. When connections are restored, they
succeed, although without optimization.
When the fault is corrected, new connections that are made receive optimization:
however, connections made during the fault are not. To force all connections to be
optimized, enable the kickoff feature. Generally, connections are short lived and
kickoff is not necessary. For detailed information about enabling the kickoff feature,
see the HP Enterprise File Services WAN Accelerator Management Console User
Guide.
TIP: You can close old connections in the Reports: Current Connections page of the
Management Console. For detailed information, see the HP Enterprise File Services WAN
Accelerator Management Console User Guide.
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 StorageWorks 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: