Friday, October 12, 2007

Disaster Recovery And Data Centers

In today’s complex and challenging market, intensive business continuity plans or state of the art disaster recovery techniques for nonstop data availability have become critical to organizations if they are to survive an outage. Most IT related disasters are actually logical disasters, such as data corruption, viruses, and human error, as opposed to physical disasters like fire, earthquakes, hurricanes, tsunami, etc. Logical disasters occur all the time and pose a bigger threat to businesses. However, because of being invisible to the general public, logical disasters tend to be taken less seriously.

Data Center Disaster Recovery is smart business no matter what industry you are in. Think about these stats for a minute. It costs the average Fortune 500 corporations $50,000 per minute of downtime (IBM). The average hourly revenue lost from downtime is $78,000 and 355 worker hours are lost for each hour of unscheduled downtime (Disaster Recovery Journal). 43% of enterprises that sustain a major disaster never reopen (Wall Street Journal). Data centers are the heart of most companies today. If and when this resource is compromised; whether by hardware failure, software failure, data corruption, or data loss; a company faces severe potential losses unless a robust data recovery plan is already in place. Below are simplified solutions that can be implemented for Disaster Recovery not only in Data Centers but also by small companies operating in an IT environment.

Situation You're Facing....

Data center companies today have to follow the continuous business paradigm, which combines high-availability solutions with state of the art disaster recovery solutions. The ultimate goal should be the ability to manage both premeditated and accidental situations with minimal or zero disruption.

When an accidental event occurs, the ideal scenario is:

- Recovery will happen almost automatically with no loss of data

- Costs of the solution and resources are minimal

- Impact to the production environment is zero

While technology is moving forward at a rapid pace to reach this ideal scenario, many other business and technological concerns exist, including some significant trade-offs dictated by technology, budgets, and personnel resources.

Simplified Data Recovery Solutions....

Recovery time objective (RTO) & Recovery point objective (RPO), along with their associated costs, are important criteria when evaluating the right solution.

- RTO describes the time frame in which business functions or applications must be restored.

- RPO describes the point in time to which data must be restored to successfully resume processing.

Many solutions are available depending on an organization’s recovery objectives. For example, when looking at the RPO, one may be concerned with the cost of some data loss (typically less than five minutes). While some may prefer to be able to quickly perform a database restart instead of a no-data-loss option, others may prioritize limiting possible impacts to the production environment and ensuring easy recovery at the secondary site.

When planning to install a Disaster Recovery solution, first, point to be considered is the Data Center’s environment. It’s important to understand that all data is not created equal. It is likely that only a portion of a corporation’s data is critical to its basic operation and that a variety of techniques could be used to secure that data, depending on the criticality of that particular business function. In general practice organizations choose not to take this approach, but to copy everything. This is a trade-off situation in terms of the cost of potentially having to re-engineer the entire environment compared to the cost of using a higher tier for all data.

Implementing a remote data replication policy is the first step towards a comprehensive disaster recovery plan, which is no longer an option but a necessity for companies operating in IT computing environments, now, let’s analyze the basic simplified disaster recovery solutions for a Data Centre of any size.

Data Replication....

Data replication is the basis of all disaster recovery solutions and involves periodically copying a volume's data onto a secondary storage device, which can be located any distance from the original. If the main storage device should fail, data on the secondary storage device can immediately be promoted to primary status and brought online. Replication is a continuous process that begins by establishing a complete copy of data at risk at the disaster recovery (secondary) site.


Data mirroring can be employed in addition to basic replication process as part of the disaster recovery solution. The process of mirroring involves the use of a “shadow” disk that is updated in parallel with the primary disk, providing a real-time or near real-time copy of the primary disk. Mirroring provides the first level of data protection with a mirror disk attached to the host machine or an appliance located at the primary site. In the event of data loss on the primary disk, the data is retrieved seamlessly from the mirror disk.

Fast Recovery....

For protection against natural/logical disasters, Data Centers require remote sites to be located hundreds of miles away from the business, raising issues of data loss and synchronization of data between the primary and data recovery site. The ideal disaster recovery solution provides quick time-to-recovery, assuring continuance of operations. Additionally, the solution must minimize data loss for a graceful recovery, keeping primary and data center’s recovery data synchronized while minimizing human intervention to reduce errors during the recovery process.

Snapshot agents minimize recovery time. When data replication is used in conjunction with snapshot agents, the data has full transactional integrity in addition to point-in-time consistency. This means the replica can be immediately put into active use without going through a complete ‘consistency check’ process that can be very time-consuming for large datacenters or databases. Simply put data recovery and replication solutions have to be flexible, easily deployable, and scalable and support rapid recovery.

Accelerating Pre and Post Disaster Operation....

During initial set up of pre-disaster operation, synchronization of data between the two sites can be done using tape backups or local mirroring and shipped to the remote site, followed by a delta-sync process to facilitate minimal transfer of data over expensive WAN links. During an emergency, an IP link may be deployed to allow emergency access of the data at the data center’s recovery site over WAN by any server located anywhere. This IP connectivity provides significant advantages, offering more ways for temporary offices to access data during an emergency. A reverse delta-sync process facilitates fast recovery of the primary site when the emergency is over.

Reducing Cost....

Data centers use Fiber Channel for their storage networks and a simplified DR solution must provide interface to MAN and WAN routers without the need for extra FC-to-IP converter boxes. These solutions also need to be independent of the type of storage subsystems, application servers and operating system platforms rather than work only in a homogeneous environment. By eliminating the need to deploy matching disk arrays, file servers or application servers at the secondary disaster recovery site, such systems can offer unprecedented flexibility in creating disaster recovery environments and allowing for low-cost DR planning by using low cost JBOD or ATA-based RAID arrays at the data center’s recovery site.

Data replication whether remote or local, is no longer an option, but a necessity for corporate enterprises and a challenge for data centers. The amount of data at risk and the cost to replace that data if in fact it can be replaced highlight the need for a data protection solution that extends beyond a building, a campus, or even a country. While most customers recognize the need for this type of data protection, they are squeezed by the continued tight IT budgets and the cost and complexity of existing solutions.

The complexity problem in DR can be solved today by using fully integrated replication solutions built on performance/cost optimized appliances. Every additional dollar spent on DR solutions by a data center puts additional burden on the data centers and increases the cost for customers. By deploying data replication, mirroring, backup and snapshot storage applications on an affordable appliance platform, a comprehensive disaster recovery and replication solution can address the key customer requirements of flexibility, ease of deployment and scalability while keeping the operational costs low for the Data Centers.

If you find you do need more bandwidth to ensure appropriate redundancy or address other disaster recovery issues....I suggest taking advantage of the free assistance to find the right solution provided here:

Bandwidth Solution


Labels: , , , ,


Post a Comment

Links to this post:

Create a Link

<< Home