HP StorageWorks Enterprise File Services WAN Accelerator - Manual (Page 46)

46 3 - S ETTING U P R EMOTE HP EFS WAN A CCELERATORS
4. Use the controls to set CIFS features for a profile, as described in the following
table.
Control Description
Settings will be applied to profile Select the name of the profile you want to configure from the drop-down list.
General Disable Write Optimization. Check this box 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 appliance 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 appliance.
If you do not disable write-through, the appliance acknowledges writes before they are
fully committed to disk, to speed up write operation. The appliance does not
acknowledge the file close until the file is safely written.
Transparent Pre-population Enable Transparent Pre-population. Check this box to enable transparent pre-
population.
To enable transparent pre-population, you must install and run the HP EFS Remote Copy
Utility (RCU) to pre-populate data on the client and server. Because the data has already
been copied to the client and server, the appliance only copies new data, increasing
optimization of traffic across the WAN. The HP EFS RCU is available at http://
www.hp.com.
Security Signature Optimize Connections with Security Signature. Check this box 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 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.