HP StorageWorks Enterprise File Services WAN Accelerator - Manual (Page 33)

HP S TORAGE W ORKS EFS WAN A CCELERATOR M ANAGEMENT C ONSOLE U SER G UIDE 33
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3. Use the controls to complete the configuration, as described in the following table.
Control Description
General Enable Latency Optimization. Latency optimization is enabled by default. Only
uncheck this box if you want disable Latency optimization. Typically, you disable
latency optimization to troubleshoot problems with the system.
Disable Write Optimization. Specify this option to disable write optimization.
Disable write optimization only if you have applications that assume and require write-
through in the network. If you disable write optimization, the HP EFS WAN Accelerator
still provides optimization for CIFS reads and for other protocols, but you might
experience a slight decrease in overall optimization.
Most applications operate safely with write optimization because CIFS allows you to
explicitly specify write-through on each write operation. However, if you have an
application that does not support explicit write-through operations, you must disable it in
the HP EFS WAN Accelerator.
If you do not disable write-through, the HP EFS WAN Accelerator acknowledges writes
before they are fully committed to disk, to speed up write operation. The HP EFS WAN
Accelerator does not acknowledge the file close until the file is safely written.
Optimize Connections with Security Signatures (that do not require signing).
Specify this option to disable Windows Server Message Block (SMB) signing.
The Secure-CIFS feature enables you to automatically disable Windows Server Message
Block (SMB) signing. SMB signing prevents the appliance from applying full
optimization on CIFS connections and significantly reduces the performance gain from
an HP EFS WAN Accelerator deployment. Because many enterprises already take
additional security precautions (such as firewalls, internal-only reachable servers, and so
forth), SMB signing adds little additional security, at a significant performance cost
(even without appliances).
Before you enable Secure-CIFS, you must consider the following factors:
• If the client-side machine has Required signing, enabling Secure-CIFS prevents the
client from connecting to the server.
• If the server-side machine has Required signing, the client and server connect but you
cannot perform full latency optimization with the appliance. Domain controllers
default to Required.
For detailed information about SMB signing and the performance cost associated with it,
see the HP StorageWorks Enterprise File Services WAN Accelerator Installation and
Configuration Guide.
Enable Dynamic Write Throttling. Enables CIFS dynamic throttling mechanism which
replaces the current static buffer scheme. If you enable CIFS dynamic throttling, it is
activated only when there are sub-optimal conditions on the server side causing a back-
log of writes messages; it does not have a negative effect under normal network
conditions.