1. Internet Connection Failover
2. Server System Replication

Internet Connection Failover
Maximizing Internet Availability

Businesses have come to rely upon access to the Internet. For many companies, the loss of Internet availability drags their productivity to a screeching halt. In order to guard against interruption, leading companies have provided reliable solutions to provide resiliency in Internet connectivity.

By using a combination of two separate Internet circuits, supplied by two different Internet Service Providers (ISPs), and two firewall appliances, continuous availability can be maintained even if a firewall or the Internet circuit itself fails. For example, two Sonicwall TZ-170 firewall appliances are each connected to a T-1 circuit supplied by MEGAPATH and a DSL circuit provided by SBC. In this configuration, Internet service will remain available even if a firewall or individual circuit becomes unavailable.

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Server System Replication
Maximizing Server and Application Availability

Organizations of all industries and sizes can not afford down time, especially in today’s competitve and demanding environment.  DTS specializes in making network environmnents "Highly Available."  Depending on the client’s objectives with regard to how quickly they want to recover in system failures (Recovery Time Objective - or "RTO") and how current that data needs to be when they recover from a system failure (Recovery Point Objective - or "RPO), will depend on what solution best suits them.

In the event that their objectives require little or no downtime, the ability to provide full scale Server System Replication becomes critical.

Through various technologies, DTS has mastered the replication of many types of servers both in a LAN and WAN environment.

Among the solutions we use are:

• Neverfail for Exchange
• Neverfail for SQL
• Neverfail for SharePoint
• Microsoft Exchange Clustering 
• Windows Distributed File System

  Abstracts taken from www.neverfailgroup.com

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Neverfail for Exchange is the most comprehensive high availability, low cost software solution for Microsoft Exchange 2000/2003

The heart and soul of Neverfail for Exchange - Neverfail Heartbeat
The most important consideration in protecting your Microsoft Exchange environment is creating a real-time, duplicate copy of your Exchange data. Neverfail Heartbeat sits at the core of Neverfail’s suite of affordable, "cluster-class" solutions, replicating data from your active to your passive server, whether they reside in the same server room, or across the globe.
Neverfail for Exchange is the only high availability solution that proactively monitors your entire Exchange environment
Neverfail for Exchange proactively monitors the health of your physical server hardware, network infrastructure, operating system, and Microsoft Exchange application. If any problem occurs, Neverfail can take a variety of preemptive, corrective actions to resolve the issue without resorting to a full system failover. In extreme cases where the issue can not be resolved, a graceful switchover to your secondary server can occur automatically, ensuring continuous Exchange availability.
Support for virtually any Auxiliary Application
In addition to protecting your Microsoft Exchange application, Neverfail can also protect auxiliary applications that you may have installed onto your server. These may include supporting applications such as anti-virus, backup, fax and archiving solutions. Our Application Module eXtension (AMX) technology provides an application program interface to easily and rapidly generate these extension products. Neverfail’s existing library of AMX is extensive; they are fully maintained and supported and remove the commercial concern and cost of "one-off" development practices on a critical server.
You’ll only find switchback capabilities in Neverfail for Exchange
In addition to offering both manual and automatic switchover capabilities, Neverfail for Exchange also features the ability to seamlessly switchback, something replication solutions can’t offer. Whether your primary server is down for several hours or even days, Neverfail will seamlessly resynchronize your servers when the primary does come back online, and allow you to switch your workload back to a normal production state within a few minutes by the simple click of a button!

Neverfail for Exchange monitors critical Microsoft Exchange services, and can take corrective action when problems arise
High availability over a LAN or WAN environment
Neverfail for Exchange can be configured to protect your email in either a LAN or WAN environment. Where bandwidth or network utilization is an issue or needs to be reduced, the Neverfail Low Bandwidth Module (LBM) is available to optimize and reduce the amount of data that is transmitted between the two servers.
KEY FEATURES
Dynamically identifies and includes specific application components

• Neverfail for Exchange intelligently discovers all application files, registry settings, services and databases associated with a specific application.
• Saves time, money and lowers risk by eliminating any customization or scripting required to support specific applications. Neverfail supports the Exchange application straight "out of the box."

Automatically monitors all key application services

• Automatically monitors the availability of all key services associated with a specific application.
• Improves availability by showing not only whether a server is available or not, but what is happening within the application.

Monitors all key application performance attributes

• Monitors all key performance aspects of the operating system, hardware and application.
• Improves availability by identifying when overall performance begins to degrade.

Preemptive failover avoidance

• Neverfail can take a variety of corrective actions to repair or resolve problems detected through its monitoring capability.
• Avoids expense of IT personnel involvement in managing unnecessary failoverss.

Seamless switchover, failover and switchback of application workload

• Automatically moves an application’s workload back and forth between primary and secondary servers.
• Improves availability by providing seamless, non-disruptive application redundancy to users.

Reliability is the first and most crucial step to achieving high availability
The successful implementation and ongoing performance of any cluster-class high availability solution is predicated upon a reliable technology platform. Neverfail’s Server Check Optimization Performance Evaluation (SCOPE) is the only automated software solution to deliver a comprehensive health "check-up" of your server environment. SCOPE identifies existing configuration and performance issues in your environment prior to installation of a high availability solution and it provides "snapshots" of your environment to ensure on-going reliability.
Neverfail for Exchange Summary
Your business communications are too important to leave to back-up or replication. And why settle for a partial solution that focuses only on recovering hardware and data failures from a primary server when Neverfail for Exchange can deliver comprehensive, proactive failure protection for all elements of your server environment? Only Neverfail for Exchange can give you a cluster-class, high availability solution that’s easy to install at approximately one tenth the cost of other cluster-class solutions.
SYSTEM REQUIREMENTS
Primary server requirements

• Microsoft Windows 2000 or 2003 compatible server with 2GB of free system hard disk space. This should not be spread over several drives.
• A minimum of 1GB RAM is recommended. Exact requirements depend on application load.
• Microsoft Windows 2000 Server or Advanced Server, or Microsoft Windows 2003 Server or Enterprise Server, latest SP version.
• Microsoft Exchange 2000 Standard or Enterprise, or Microsoft Exchange 2003 Standard or Enterprise, latest SP version.

Secondary server requirements

• Microsoft Windows 2000 or 2003 compatible server with disk space and memory to match the Primary Server.
• Same version of operating system with the same Service Pack applied as the Primary Server.
• License for Microsoft Exchange, same version as Primary server.

Network requirements

• 2 Network cards per machine (1 Public & 1 Channel) or 3 Network cards per machine (1 Public & 2 Channel).

Licensing

• Neverfail for Exchange is licensed based on the Server in a pair with the greatest number of CPUs.

Neverfail for SQL Server is the most comprehensive high availability, low cost software solution for Microsoft SQL Server.

The heart and soul of Neverfail for SQL Server - Neverfail Heartbeat
The most important consideration in protecting your Microsoft SQL Server environment is creating a real-time, duplicate copy of your SQL data. Neverfail Heartbeat sits at the core of Neverfail’s suite of affordable, "cluster-class" solutions, replicating data from your active to your passive server, whether they reside in the same server room, or across the globe.
Neverfail for SQL Server is the only high availability solution that proactively monitors your entire SQL environment
With new databases being created, data being appended, changed, deleted and more, SQL Server environments never stand still- they’re subject to constant change. Neverfail for SQL Server proactively monitors your SQL Server application, including all system and data tables, looking for just such changes. It then reconfigures itself accordingly to ensure any and all changes are included in its replication set.
In addition to monitoring the SQL application, Neverfail for SQL Server is the only cluster-class, high availability solution to proactively monitor the health of your entire SQL environment, including: physical server hardware, network infrastructure and operating system. If any problem occurs, Neverfail can take a variety of preemptive, corrective actions without resorting to a full system failover. In extreme cases, a graceful switchover to your secondary server can occur automatically, ensuring continuous SQL availability.
Support for virtually any Auxiliary Application
Neverfail can also protect auxiliary applications that you may have installed onto your server. These may include supporting applications such as anti-virus, backup and archiving solutions. Our Application Module eXtension - AM(X) - technology provides an application program interface to easily and rapidly generate these extension products.

Neverfail for SQL Server monitors SQL system performance and can take preemptive action when performance degrades.
High availability over a LAN or WAN environment
Neverfail for SQL Server can be configured to protect your database applications in either a LAN or WAN environment. Where bandwidth or network utilization is an issue or needs to be reduced, the Neverfail Low Bandwidth Module (LBM) is available to optimize and reduce the amount of data that is transmitted between the two servers.
You’ll only find switchback capabilities in Neverfail for SQL Server
In addition to offering both manual and automatic switchover capabilities, Neverfail for SQL Server also features the ability to seamlessly switchback, something replication solutions can’t offer. Whether your primary server is down for several hours or even days, Neverfail will seamlessly resynchronize your servers when the primary does come back online, and allow you to switch your workload back to a normal production state within a few minutes by the simple click of a button!
Reliability is the first and most crucial step to achieving high availability
The successful implementation and ongoing performance of any cluster-class high availability solution is predicated upon a reliable technology platform. Neverfail’s Server Check Optimization Performance Evaluation (SCOPE) is the only automated software solution to deliver a comprehensive health "check-up" of your server environment. SCOPE identifies existing configuration and performance issues in your environment prior to installation of a high availability solution and it provides "snapshots" of your environment to ensure on-going reliability.
Neverfail for SQL Server Summary
Your databases are the lifeblood of your business and are too important to leave to back-up or replication. And why settle for a partial solution that focuses only on recovering hardware and data failures from a primary server when Neverfail for SQL Server can deliver comprehensive, proactive failure protection for all elements of your server environment? Only Neverfail for SQL Server can give you a cluster-class, high availability solution that’s easy to install and approximately one-tenth the cost of other cluster-class solutions.
KEY FEATURES
Dynamically identifies and includes specific application component

• Neverfail for SQL Server intelligently discovers all application files, registry settings, services and databases associated with a specific application.
• Saves time, money and lowers risk by eliminating any customization or scripting required to support specific applications. Neverfail supports the SQL Server application straight "out of the box."

Automatically monitors all key application services

• Automatically monitors the availability of all key services associated with a specific application.
• Improves availability by showing not only whether a server is available or not, but what is happening within the application.

Monitors all key application performance attributes

• Monitors all key performance aspects of the operating system, hardware and application.
• Improves availability by identifying when overall performance begins to degrade.

Preemptive failover avoidance

• Neverfail can take a variety of corrective actions to repair or resolve problems detected through its monitoring capability.
• Avoids expense of IT personnel involvement in managing unnecessary failoverss.

Seamless switchover, failover and switchback of application workload

• Automatically moves an application’s workload back and forth between primary and secondary servers.
• Improves availability by providing seamless, non-disruptive application redundancy to users.

SYSTEM REQUIREMENTS
Primary server requirements

• Microsoft Windows 2000 or 2003 compatible server with 2GB of free system hard disk space. This should not be spread over several drives.
• A minimum of 1GB RAM is recommended. Exact requirements depend on application load.
• Microsoft Windows 2000 Server or Advanced Server, or Microsoft Windows 2003 Server or Enterprise Server, latest SP version.
• Microsoft SQL Server 2000 Standard or Enterprise, latest SP version.

Secondary server requirements

• Microsoft Windows 2000 or 2003 compatible server with disk space and memory to match the Primary Server.
• Same version of operating system with the same Service Pack applied as the Primary Server.

Network requirements

• 2 Network cards per machine (1 Public & 1 Channel) or 3 Network cards per machine (1 Public & 2 Channel).

Licensing

• Neverfail for SQL Server is licensed based on the Server in a pair with the greatest number of CPUs.

Neverfail for SharePoint is the only fully integrated high availability, low cost software solution for the entire Microsoft SharePoint environment.

Remember the white board meetings where everyone sat around a conference room brainstorming? With Microsoft SharePoint, those days are over… web sites have replaced white boards and collaboration can take place around the world. How much would it cost your company in lost productivity to go a day without Microsoft® SharePoint? With Neverfail for SharePoint, you’ll never have to know.
Neverfail for SharePoint protects and proactively monitors your entire SharePoint environment, including all connected systems and applications
With new collaborative content being generated, changed, deleted, and more, SharePoint environments never stand still - they’re subject to constant change. Microsoft clustering cannot protect your SharePoint Portal Server; Neverfail for SharePoint is the only high availability solution that ensures end-to-end protection for your entire SharePoint environment, including all information sharing applications and collaborative servers. With Neverfail, your users stay connected to working applications at all times.
In addition to monitoring the SharePoint Portal Server, Neverfail for SharePoint will also protect the servers that host your valuable SharePoint content - whether it resides in SQL Server, Exchange Public Folders or on a file system. Furthermore, Neverfail is the only cluster-class, high availability solution to proactively monitor the health of your entire SharePoint environment, including: physical server hardware, network infrastructure and operating system. If any problem occurs, Neverfail can take a variety of preemptive, corrective actions without resorting to a full system failover. In extreme cases, a non-disruptive, seamless failover to your secondary server can occur automatically and transparently to your users.
Support for virtually any Auxiliary Application
Neverfail can also protect auxiliary applications that you may have installed onto your server. These may include supporting applications such as anti-virus, backup and archiving solutions. Our Application Module eXtension - AM(X) - technology provides an interface to easily and rapidly generate these extension products.

Neverfail for SharePoint monitors SharePoint system performance and can take preemptive action when performance degrades.
The heart and soul of Neverfail for SharePoint - Neverfail Heartbeat
One of the most important considerations in protecting your Microsoft SharePoint environment is creating a real-time, duplicate copy of your SharePoint environment. Neverfail Heartbeat sits at the core of Neverfail’s suite of affordable, "cluster-class" solutions, replicating data from your active to your passive server, whether they reside in the same server room, or across the globe.
You’ll only find switchback capabilities in Neverfail for SharePoint
In addition to offering both manual and automatic switchover capabilities, Neverfail for SharePoint also features the ability to seamlessly switchback, something replication solutions can’t offer. Whether your primary server is down for several hours or even days, Neverfail will seamlessly resynchronize your servers when the primary does come back online, and allow you to switch your workload back to a normal production state within a few minutes by the simple click of a button!
High availability over a LAN or WAN environment
Neverfail for SharePoint can be configured to protect your service in either a LAN or WAN environment. Where bandwidth or network utilization is an issue or needs to be reduced, the Neverfail Low Bandwidth Module (LBM) is available to optimize and reduce the amount of data that is transmitted between the two servers.
Reliability is the first and most crucial step to achieving high availability
The successful implementation and ongoing performance of any cluster-class high availability solution is predicated upon a reliable technology platform. Neverfail’s Server Check Optimization Performance Evaluation (SCOPE) is the only automated software solution to deliver a comprehensive health "check-up" of your server environment. SCOPE identifies existing configuration and performance issues in your environment prior to installation of a high availability solution and it provides "snapshots" of your environment to ensure on-going reliability.
Neverfail for SharePoint Summary
Your collaborative content is the lifeblood of your business and is too important to leave to back-up or replication. And why settle for a partial solution that focuses only on recovering hardware and data failures from a primary server when Neverfail for SharePoint can deliver comprehensive, proactive failure protection for all elements of your server environment? Only Neverfail for SharePoint can give you a cluster-class, high availability solution that’s easy to install and approximately one-tenth the cost of other cluster-class solutions.
KEY FEATURES
Dynamically identifies and includes specific application components

• Neverfail for SharePoint intelligently discovers all application files, registry settings, services and data associated with Microsoft SharePoint Portal Server and collaborative servers, including SQL Server, File Servers and Exchange.
• Saves time, money and lowers risk by eliminating any customization or scripting required to support specific applications. Neverfail supports all of your SharePoint servers straight "out of the box."

Automatically monitors all key application services

• Automatically monitors the availability of all key services associated with SharePoint and collaborative servers.
• Improves availability by showing not only whether a server is available or not, but what is happening within Sharepoint.

Monitors all key performance attributes

• Monitors all key performance aspects of the operating system, hardware and Sharepoint application and all collaborative servers.
• Improves availability by identifying when overall performance begins to degrade.

Preemptive failover avoidance

• Neverfail can take a variety of corrective actions to repair or resolve problems detected through its monitoring capability.
• Avoids expense of IT personnel involvement in managing unnecessary failovers.

Seamless switchover, failover and switchback of workload

• Automatically moves workload back and forth between primary and secondary portal and collaborative servers with no impact to end users
• Ensures seamless, non-disruptive availability of your entire Sharepoint environment, so users stay connected to working applications.

SYSTEM REQUIREMENTS
Primary server requirements

• Microsoft Windows 2003 compatible server with 2GB of free system hard disk space. This should not be spread over several drives.
• A minimum of 1GB RAM is recommended. Exact requirements depend on application load.
• Microsoft Windows 2003 Server or Enterprise Server, latest SP version.
• Microsoft SharePoint Portal Server 2003, latest SP version.

Secondary server requirements

• Microsoft Windows 2003 compatible server with disk space and memory to match the Primary Server.
• Same version of operating system with the same Service Pack applied as the Primary Server.

Network requirements

• 2 Network cards per machine (1 Public & 1 Channel) or 3 Network cards per machine (1 Public & 2 Channel).

Licensing

• Neverfail for SharePoint is licensed based on the Server in a pair with the greatest number of CPUs.

Abstracts taken from www.microsoft.com

Exchange 2003 Clustering Features

Exchange 2003 offers many clustering improvements, including support, performance, and security improvements. The following are some of the significant Exchange 2003 clustering features:

The following sections discuss these features in detail.
Some of the improvements to clustering discussed in this section become available when using Windows Server 2003 in conjunction with Exchange 2003. For information about additional benefits of using Windows Server 2003 for your Exchange 2003 clusters, see Technical Overview of Windows Server 2003 Clustering Services .

Support for Up to Eight-Node Clusters

Exchange 2003 enhances clustering capabilities by introducing support for eight-node Exchange clusters. Eight-node clusters are supported only when running Windows Server 2003, Enterprise Edition or Windows Server 2003, Datacenter Edition. Another requirement for clusters with three or more nodes is that at least one node must be passive. For complete details about the supported cluster configurations based on Windows and Exchange editions, see "Windows and Exchange Edition Requirements" in Understanding Exchange Server 2003 Clustering .
All Exchange 2003 clustering recommendations are for active/passive cluster configurations. For information about active/passive and active/active cluster configurations, see "Cluster Configurations" in Understanding Exchange Server 2003 Clustering .
Support for Volume Mount Points
Volume mount points are now supported on shared disks when the nodes of your cluster are running Window Server 2003, Enterprise Edition or Windows Server 2003, Datacenter Edition. Volume mount points are directories that point to specified disk volumes in a persistent manner. (For example, you can configure C:\Data to point to a disk volume.) Mount points bypass the need to associate each disk volume with a drive letter, thereby surpassing the 26-drive letter limitation.
For more information about volume mount points, see "Windows Server 2003 Volume Mount Points" in Planning Considerations for Clustering .
Improved Failover Performance
For clustering in Exchange 2003, the amount of time it takes for a node to fail over to another node is reduced, thereby improving overall performance. The following sections provide information about the improvements to failover times.
Improved Dependency Hierarchy for Exchange Services
To decrease the amount of time it takes to fail over a server, Exchange 2003 provides an improved dependency hierarchy for Exchange services. Specifically, in Exchange 2000, the Exchange protocol services are dependent on the Microsoft Exchange Information Store service. However, in Exchange 2003, these services are dependent on the Microsoft Exchange System Attendant service.

Hierarchy of Exchange dependencies in Exchange 2000

Hierarchy of Exchange dependencies in Exchange 2003
In Exchange 2003, the Internet Message Access Protocol version 4rev1 (IMAP4) and Post Office Protocol version 3 (POP3) resources are not created automatically when you create a new Exchange Virtual Server (EVS).
If a failover occurs, this improved hierarchy allows the Exchange mailbox stores, public folder stores, and Exchange protocol services to start simultaneously. As a result, all Exchange resources (except the System Attendant service) can start and stop simultaneously, thereby improving failover time. Additionally, if the Exchange store stops, it no longer must wait for its dependencies to go offline before the store resource can be brought back online
Improved Detection of Available Nodes
When running Exchange 2003 on Windows Server 2003, the Cluster service automatically detects the available node. The overall time it takes for Exchange to fail over to the available node is reduced. Therefore, for both planned and unplanned failovers, downtime is reduced.
Improved Security
Exchange 2003 clustering includes the following security features:

The following sections discuss each of these features in detail.
Clustering Permission Model Changes
The permissions needed to create, delete, or modify an EVS are modified in Exchange 2003. The best way to understand these modifications is to compare the Exchange 2000 permissions model with the new Exchange 2003 permissions model.
In the following sections, the term cluster administrator refers to the person who manages Exchange clusters for your organization.
Exchange 2000 Permissions Model
For an Exchange 2000 cluster administrator to create, delete, or modify an EVS, the cluster administrator’s account and the Cluster service account require the following permissions:

Exchange 2003 Permissions Model
In Exchange 2003, the permissions model has changed. The Windows Cluster service account is no longer Exchange-specific. This means that the Cluster service account no longer requires that the Exchange Full Administrator role be applied to it, neither at the Exchange organizational level nor at the administrative group level. The default permissions for the Cluster service account in the forest are sufficient for it to function in Exchange.
As with Exchange 2000, the cluster administrator requires the following permissions:

However, depending on the mode in which your Exchange organization is running (native mode or mixed mode) and on the configuration of your topology, your cluster administrators must have the following additional permissions:

Kerberos Enabled by Default on Exchange Virtual Servers
Kerberos is the authentication protocol in Microsoft Windows 2000 Server and later that provides mutual authentication. However, the Cluster service did not support Kerberos enabled cluster groups until Service Pack 3 (SP3) for Windows 2000. Because of this, the older authentication protocol, NTLM, was the default authentication protocol for Exchange servers running in clusters.
Because Kerberos is supported in the Cluster service on Windows 2000 with SP3 or later or Windows Server 2003 and Exchange 2003, Kerberos is enabled by default when you create an EVS on a server running Windows Server 2003 or Windows 2000 with SP3.
IPSec Support from Front-End Servers to Clustered Back-End Servers
You can use IPSec if a secure channel is required between front-end and back-end cluster servers. This configuration is fully supported when both the front-end servers and back-end servers are running Exchange 2003 on Windows Server 2003.
IMAP4 and POP3 Resources Not Added by Default
For improved security, when you create an EVS, the IMAP4 and POP3 protocol resources are no longer created. For more information about enabling IMAP4 or POP3, see "Managing Exchange Clusters," in the Exchange Server 2003 Administration Guide .
Checking Clustering Prerequisites
To ensure that your clusters meet certain requirements, Exchange 2003 performs more prerequisite checks on clusters than previous versions of Exchange. For example, to help make sure that Exchange is correctly installed on your cluster nodes, Exchange 2003 performs more pre-installation checks on the cluster nodes. Similarly, to help make sure that your EVSs are correctly configured, Exchange 2003 performs more checks on your cluster when creating and removing EVSs.
For a complete list of the prerequisite checks that Exchange performs, see the following resources:

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