Disaster Recovery Planning

It's a fact of business life - physical, natural, and digital disasters do occur, and they interrupt operations and impact revenue. Your level of preparation and planning will determine your ability to recover from a disaster. Dramatic lessons about this topic have been learned in the past few years, yet some businesses remain unprepared. This much is certain - those prepared are able to withstand disasters, while those that are unprepared risk heavy losses.

Disaster Recovery (DR) revolves around getting back to business as quickly as possible after a failure or error. The ability to recover is directly tied to the preparations that have been made before a disaster occurs, i.e. your Business Continuity plans.

Once trouble hits, it can be too late. You need a Business Continuity plan that balances potential business losses against the cost of minimising those losses. You must understand your business needs, potential disruptions, and loss tolerance in order to prepare responsibly. With that knowledge and an understanding of the technology options available today, you can design your environment to avoid disasters (for example, using redundancy and hot-serviceable components) as well as develop a disaster recovery plan that's right for you business.

There are four key stages to developing solid Business Continuity plans and ensuring rapid disaster recovery:

  1. Identify your needs and define what Business Continuity means to you
  2. Determine and document your recovery objectives
  3. Evaluate technologies that support your strategy
  4. Implement and test the technologies best suited to your requirements

By applying these steps to your organisation will help you minimise losses when disaster strikes.

1: What Business Continuity means to your business

Disasters commonly occur in two forms

Data destruction is far more frequent and is easier to prevent.

The cost of operational downtime varies among businesses and industries. For example, financial firms often calculate that cost in millions of pounds per hour, while other industries calculate operational downtime as thousands per day. These costs include lost business transactions, employee productivity and customers, not to mention regulatory penalties (though these are less frequent). The ability to tolerate these losses generally determines Business Continuity strategy and the associated budget.

2: Determine and document your business's tolerance to downtime

How long can your business afford to be non-operational, and how much work/data can you afford to lose? Does Business Continuity for you mean restarting business within minutes with current data? Can you tolerate restarting within hours with several hours of work/data loss? The categories below outline questions you need to answer for your organisation. Documenting your answers will help you plan.

In addition, you must determine what level of investment you can tolerate to protect against downtime and to recover from it. (It is important to note that higher cost does not necessarily mean higher levels of Business Continuity. Different technologies provide different kinds of protection).

Have you configured your environment so that more common errors (such as loss of disks or controllers) don't become DR scenarios? Avoiding disasters is an important part of disaster planning.

3: Evaluate Disaster Recovery technologies

At ADA we spend considerable time assisting customers with their DR initiatives. We invest huge time and efforts in evaluating new products for inclusion into our solution portfolio. DR related technologies continue to improve, providing lower costs and increased efficiencies.

ADA provides too many DR products to list within this article; the following provides a sample of hot technologies that ADA is implementing for our customers:

Virtualisation: VMware

It is a fact that traditional Disaster Recovery solutions are costly, complex and frequently do not meet recovery objectives. They are costly because they require significant investments in hardware and in specialised software. Recovery frequently requires complex, time-consuming multi-step processes. Meeting recovery time objectives is difficult because of the complexity and cost of advanced solutions.

VMware Virtual Infrastructure provides a solution that makes it possible to implement Disaster Recovery plans at a significantly lower cost. Traditional Disaster Recovery plans require that recovery target hardware must exactly duplicate production hardware, effectively doubling hardware requirements for protected applications. In contrast, VMware virtual machines are hardware-independent and thus any physical server can serve as a recovery target for any virtual machine.
As a result, organisations can significantly reduce the cost of hardware for disaster recovery by repurposing underutilised existing servers for recovery targets and DR testing.

Virtualisation: Replication

VMware virtual infrastructure simplifies and accelerates recovery, helping achieve Recovery Time Objectives targets. Single-step file recovery is achieved because virtual machines are completely encapsulated in a small number of files and can be restored to any hardware. This encapsulation property also makes it possible to use third-party replication software such as Vizioncore esxReplicator to replicate entire virtual machines to a recovery site, reducing recovery time to just a few hours.

Virtualisation: P2V and Bare Metal Snapshots for DR

Physical servers can be recovered to virtual machine recovery targets in a “physical-to-virtual” recovery scenario, providing the benefits of simpler and hardware-independent recovery and using either:

“Symantec Backup Exec Systems Recovery is one of the best products we install at the moment. It does exactly what is says it does and customers are really pleased with the results”" Ian Slater, ADA Projects Manager

FACT: VMware virtual infrastructure enables a better Disaster Decovery plan whether or not organizations have virtualized their production servers.

Storage: SAN to SAN replication

To enable consistent data between primary and recovery sites the most reliable and efficient method is to replicate backend SAN based storage to another similar SAN. Many storage vendors provide replication solutions, NetApp provide their Snapmirror product, EqualLogic provide Auto-Replication and EMC has MirrorView.

Storage: DAS/NAS to DAS/NAS replication

Data replication is not limited to SAN based storage; using host based replication software such as Double-Take allows asynchronous replication and additional failover technologies. Double-Take captures and replicates data changes, as they happen, to a secondary storage array in any location, allowing recovery from that location in seconds in the event of disaster. It takes the recovery process a stage further, allowing intelligent host and application failover for file serving, MS Exchange or SQL. ADA has also configured various ERP applications and email vaulting for resilience.

A new hybrid of SAN and NAS has recently been released by HP; called the All-in-One, it uses SATA and SAS. It serves both data and application storage and has integrated Asynchronous Replication allowing two or more devices to be configured to support high data availability.

4: Implement and test your DR Plan and Solution

Once you understand your needs, budget, and expectations and have selected the technology that suits your situation, implement it in your environment. To ensure that your Business Continuity plan will function as you want, you should perform a Disaster Recovery dress rehearsal. Walk through your plan, rebuild your application environment, and solicit business users to test their applications. Whatever the outcome, use that information as feedback to refine your process.

If you are not accomplishing your recovery time, recovery point, budget, or business objectives, you can tune the plan and the technology. Most important, as your business changes, your needs will change - and you should adjust your Business Continuity plan accordingly. This is not a process to put in place and forget about until a disaster occurs - review your plan and process from time to time to ensure that you are fully prepared.

ADA - Disaster Recovery Resources

As well as technology solutions, ADA provides a wide range of professional services to support each stage of DR planning, testing and refinement. The extensive ADA lab environment has also provided many customers with facilities for testing their DR initiatives with, of course, the advantage of the assistance of ADA staff.

Disaster Recovery. Managed

As the Editorial from Roger Woodcock says, ADA has continued to develop our bespoke Managed Services, many of which now provide essential components of customer's DR initiatives. All ADA Managed Services provide the certainty that they are a perfect fit as they are tailored to requirements and are fully managed by technical experts at ADA. Our current Managed Services in the DR space include:

All ADA managed technology solutions encompass a software layer providing proactive monitoring and reporting on the health and status of the service and are supported by a 24/7 helpdesk facility.