Introduction to Data replication

By 08/04/2013Uncategorized
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When it comes to protecting the efficacy and profitability of one’s business, all preventative measures to mitigate disaster should be taken. Any number of disaster recovery solutions can be utilized, but they must involve some degree of data replication and backup. Ensuring that the important information contained within your IT environment is protected is of the utmost importance to maintaining a consistent and secure environment. There are multiple ways to go about replicating and recovering necessary data, and the route that is chosen is highly dependent on the preferences of the client.

Maintaining the security and integrity of ones existing data is always important, but even more so in the case of potential disaster. Data replication that stores copies in one or more separate locations can ensure the quick and effective recovery of data after loss occurs. The longer it takes to recover data, the longer a business will be ineffective in today’s highly technological-dependent world. Whether it is a natural or manmade disaster, having backup data in a physically separate location that remains readily accessible when needed, is always a necessary step for any business.

Although data replication is a necessary step for any business wishing to have disaster recovery solution, it does add complexity to existing IT storage. Business owners should know the basic terminology and concepts behind replication of data. Firstly, any given data recovery strategy should be aligned with the business model, price point, and priorities. Having priorities about what exactly the business would like to prepare for is vital before delving into any technical discussions.

Businesses need to ascertain how long the lifecycle of the data they wish to replicate should be. Any given business will likely have records stretching back for as many years as they have been in operation; not all of this data is vital, or even desirable to backup. Needlessly backing up data that is unimportant to the daily operation of a business will take up extra physical and bandwidth space, and cost a great deal more. The first step before choosing a data replication pathway is to understand how much backup space is needed, and how much the business is willing to spend to do so.

Data replication to an off-site location is the norm for disaster recovery, but the distance between locations is dependent on the results of impact analysis and risk assessment. The distance between off-site replication sites and central IT operation will also determine the type of replication that is chosen. For example, for longer distances, businesses may want to opt for SAN based backup; whereby replication is incorporated into the SAN infrastructure. SAN based replication is easily integrated into an application or database environment when paired with mirroring and snapshot functionality. However, due to data being written on both primary and remote site storage, the primary data path is delayed slightly.

When it comes to choosing between synchronous or asynchronous mode for data replication, business priorities come to the fore. Synchronous replication entails updating a data volume at the primary site to a secondary site, ensuring that the latter has an identical data volume at any given time. Synchronous replication protects the continuous integrity of all data transferred between sites with little risk of loss during the replication period. This method, however, is more sensitive to distance, and is best suited for off-site data centers within a reasonable distance of central processing. This distance delay varies depending on the link latency and available bandwidth that allows for quicker or slower response time. Asynchronous replication does not have this limitation, and can be utilized over long distances, but is less reliable when it comes to data loss; some loss in the replication process will occur; the amount is dependent on rate of change and link speed.

When it comes to preparing for disaster recovery, any business should have a data recovery scheme in place. Preparing for the unpredictable events that will inevitably occur in your business or another is essential to ensure the continued maintenance of business integrity. Whether opting for synchronous or asynchronous replication, choosing the replication strategy that best suits one’s business location, price point and priorities is of the utmost importance.

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