I recently recorded a video session with Tim Bardzil and Eric Wolf, two team members of the Citrix Wanscaler Product Marketing group. The video is a Frequently Asked Questions session on the Citrix Systems Branch Repeater. This video can be used to address some of the common hardware and feature capabilities of the Branch Repeater.

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This is the second blog in my series on Wan Optimization and Distributed Storage.
 
Remote Copy provides a powerful and flexible method for reproducing data and keeping that replicated data available for disaster recovery, business continuance, backup and recovery, data migration and data mining. For example in figure 1 the accounting department in Chicago runs a corporate accounting application and stores the resulting data. The designated backup site is in San Francisco. Nightly at 11:00 p.m., accounting updates are copied to the San Francisco facility using Remote Copy. Remote copying follows a three-step process.

1. Creation of a primary snapshot at the Chicago facility - this is called the primary snapshot, 2. Creation of a remote volume at the San Francisco office. Then you create a remote copy of the primary snapshot to the remote volume. 3. The system then copies data from the primary snapshot to the remote snapshot.

So, you ask "what is a snapshot?" A storage snapshot is a set of reference markers, or pointers to data stored on a storage area network (SAN). A snapshot is something like a detailed table of contents, but it is treated as a complete data backup.There are two types of snapshots - the first being the copy-on-write which creates a snapshot of changes to existing data every time the data is modified or new data is added to the volume. The second is split-mirror which creates a snapshot of all the existing data including the new and updated data. Copy-on-write involves the transfer of less amounts of data than the split-mirror method.

In a typical Distributed Storage environment Copy-on-write snapshots are scheduled for daily or weekly copies from primary to remote sites. These snapshots transfer data over a Wide Area Network and by utilizing Wanscaler Wan Optimization devices at both sites these data transfers are accelerated the time of complete transfer of the data is greatly reduced. In my next blog I will demonstrate Remote Copying within a Distributed Storage environment both with and without Wan Optimization to show the dramatic decrease in transfer times. 

In my next blog I will demonstrate remote copying and snapshots both with and without Wan Optimization via a video capture highlighting the results. 

This is the first blog in a series of posts in which I will describe Citrix WanScaler operations within a Distributed Storage Area Network environment.
The purpose of this blog is to discuss the term "The Big Push" as it relates to Distributed Storage Area Networks. Distributed Storage Area Networks allow for corporations to provide local storage at Remote offices. These networks also provide remote users access to critical data in the event of a network outage.

Distributed SAN's are typically deployed in a multi-site configuration with one or more storage units located at each individual remote office, and with several clustered arrays residing at a central facility. In the example below, a corporation has it's headquarters located in San Francisco with remote offices in Chicago and New York City.

"The Big Push" is the process of the initial writing of data to a Storage Area Network array. The size of the initial datastore can be in excess of 1 terabyte. Because of this fact, "The Big Push" has been traditionally performed locally at a central facility over a high bandwidth Local Area Network where latency and bandwidth constraints are not a limiting factor. After the units have had data written to them they are then shipped to their respective remote locations and configured by local IT or contracted personnel.

By utilizing a WAN optimization solution between headquarters and the remote locations, corporations are able to deploy and complete initial configuration of remote SAN units over high latency, low bandwidth Wan links. Initial lab testing results show a significant increase in Wan performance when utilizing Citrix WanScalers between the HQ and remote sites. These results may present a compelling argument to many corporations to begin migrating from the traditional "Big Push" to a more distributed initial configuration which would eliminate the costs and logistical overhead of configuring centrally and providing support for the local installation of the remote storage units.

In my next blog post I will write about Snap-shots and how Citrix Wanscaler increases their performance metrics over a distributed environment.

This video TIP will demonstrate how to disable SMB signing within a CIFS environment. The Citrix WanScaler optimizes the Microsoft CIFS protocol, this protocol which was designed for a LAN environment has a very high overhead and is bandwidth intensive. CIFS deployed over a WAN environment may provide unpredictable performance and user experience. 

SMB signing digitally signs the CIFS protocol between two Micosoft servers. When SMB signing is enabled then the WanScaler cannot inspect the signed CIFS traffic. One must note, that even with SMB enabled the WanScaler will acccelerate layer 4 TCP traffic and some performance improvement will be seen. If an administrator wishes to experience the high gains of actually optimizing CIFS you must disable SMB.

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Monitoring the Wanscaler This is the fouth video in the four part series of configuring a Wanscaler environment for FTP demonstrations. The first in this series is Configuring the W2K3 machine. The second is configuring the XPclient, third is configuring the Linktropy Wan simulator, and fourth is monitoring the Wanscaler

Configuring the Linktrophy. This is the third video in the four part series of configuring a Wanscaler environment for FTP demonstrations. The first in this series is Configuring the W2K3 machine. The second is configuring the XPclient, third is configuring the Linktropy Wan simulator, and fourth is monitoring the Wanscaler

Configuring the XPclient. This is the second video in the four part series of configuring a Wanscaler environment for FTP demonstrations. The first in this series is Configuring the W2K3 machine. The second is configuring the XPclient, third is configuring the Linktropy Wan simulator, and fourth is monitoring the Wanscaler

Configuring the W2K3 server for FTP transfer. This is the first video in the four part series of configuring a WanScaler environment for FTP demonstrations. The first in this series is Configuring the W2K3 machine. The second is configuring the XPclient, third is configuring the Linktropy Wan simulator, and fourth is monitoring the Wanscaler.

This is the second video in a two part series showing CIFS acceleration over a WAN link using Wanscaler. This video will demonstrate the amount of CIFS optimization that occurs in a Wanscaler environment. 

 Here is a video demonstration of Microsoft CIFS acceleration over WanScaler. Equipment used for this demo were Microsoft W2K3 server, an XP client, and a Linktrophy Apposite WAN simulator.

Although, the demonstration seems very simplistic CIFS acceleration represents a milestone in WAN acceleration and data networking, in general. CIFS is the protocol that is used by Microsoft Servers and clients to exchange information. The protocol was originally designed to function over a LAN environment with a minimum of 10 Mbps throughput, half-duplex. As enterprises began expanding their data services to remote offices CIFS, designed for a LAN was being used over low bandwidth, high latency WAN's. Performance and end-user experience vary greatly in this enviornment, and the protocol provides a very high, inefficient overhead. With an accelerator between the remote and central office, TCP transmissions are optimized and thus the protocol is streamlined. Users can now experience LAN like performance while being thousand's of miles away from HQ.

h.1 Watch this videotip