HP StorageWorks Enterprise File Services WAN Accelerator - Manual (Page 38)

38 2 - C ONFIGURING THE HP EFS WAN A CCELERATOR
10. Click Save to write your settings to memory or click Reset to return the settings to
their previous values.
TIP: To remove a rule, click the check box next to the name and click Remove Selected Rules.
This action applies the settings to the running configuration. Click Save to write your settings to
memory or click Reset to return the settings to their previous values.
Enabling CIFS
Protocol
Options
Optionally, you can enable the following Common Internet File Service (CIFS)
options in the Setup: Optimization Service - Protocol: CIFS page:
‹ Disable Write Optimization (Require Write-Through). You disable CIFS
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.
‹ Enable Transparent Prepopulation. To enable CIFS transparent prepopulation
you must install and run the HP EFS Remote Copy Utility (RCU) to prepopulate
data on the client and server. Because the data has already been copied to the
client and server, the HP EFS WAN Accelerator only copies new data, increasing
optimization of traffic across the WAN. The RCU is available for download from
the HP support site at http://www.hp.com.
‹ Optimize Connections with Security Signatures.The Secure-CIFS feature
enables you to automatically disable Windows Server Message Block (SMB)
signing. SMB signing prevents the HP EFS WAN Accelerator from applying full
optimization on CIFS connections and significantly reduces the performance gain
from a 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 HP EFS WAN Accelerators).
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 HP EFS WAN
Accelerator. 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.