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

84 8 - PROXY FILE SERVICE DEPLOYMENTS
The proxy-file server can export data volumes in local mode and broadcast
mode. After receiving the initial copy of the data and ACL, the shares can then
be made available to local clients. Local client’s shares will periodically be
synchronized with the origin server and vice versa depending on the PFS
mode appropriate to your configuration.The HP EFS WAN Accelerator uses
Scalable Data Referencing (SDR) during the synchronization process which
optimizes the traffic.
To synchronize the data volumes, the HP EFS WAN Accelerator
communicates to the HP EFS RCU running on the origin server. If the origin
server cannot run the HP EFS RCU (it is a non-Windows file server), then the
HP EFS RCU can be run on a Windows server mapped to the origin server
acting as the proxy-file server.
PFS Operating
Modes
PFS can be configured with any number of file shares. Each individual file
share on the HP EFS WAN Accelerator must be configured in one of the
following operating modes:
 Broadcast Mode. Provides branch-office HP EFS WAN Accelerators with
local read-only copies of data stored on the origin server. CIFS clients who
map a Broadcast mode file share on the HP EFS WAN Accelerator cannot
make changes to the files in that file share. The data is updated
periodically on the HP EFS WAN Accelerator with the data from the
origin server. You specify the frequency of updates (synchronization)
when you configure a share.
NOTE: If a file is set with a read-only attribute on the origin server, when it is
transferred to the HP EFS WAN Accelerator, the read-only attribute is not preserved. If
a client sets the read-only attribute on a file on the HP EFS WAN Accelerator, it is
reflected in the file permissions. When this file is transferred to the origin file server, the
read-only attribute is dropped.
 Local Mode. Provides read-write access to a given file share hosted on the
branch-office HP EFS WAN Accelerator. CIFS clients mapping a Local
mode file share have read-write access to that share. Changes made to the
share are sent back to the origin server.
For any remote path, there can exist only one local share on an HP EFS
WAN Accelerator, this prevents conflicting data from being written to the
same path.
When you configure a local share, a text file (._rbt_share_lock. txt), is
created on the origin server that keeps track of which HP EFS WAN
Accelerator owns the share. Do not remove this file. If you remove
the._rbt_share_lock. txt file on the origin file server, PFS will not function
properly.
For detailed information about configuring shares in Local mode, see the
HP EFS WAN Accelerator Deployment Guide.