What alternatives are there to legacy backups, and are higher standards expected today for the recovery of lost data?
Written by Vision Solutions
Editor's Note: This article is an extract of the white paper Achieving Rapid Data Recovery for IBM AIX Environments: An Executive Overview of EchoStream for AIX available for free download from the MC White Paper Center.
Planning for recovery is a requirement in businesses of all sizes. In implementing an operational plan that ensures that both data and applications can be recovered, IT personnel are generally confronted with several challenges:
- How can I ensure my applications and data are recoverable without impacting business operations?
- Do I have data protection approaches available to me that meet my recovery point and recovery time objectives?
- Can I afford to implement a comprehensive plan that covers both my local and remote (disaster) recovery requirements?
- Are there cost-effective alternatives that meet my requirements?
Business requirements are not the only mandates that may be driving the evolution of your recovery plan. Various industry- specific regulatory mandates, including Sarbanes-Oxley, HIPAA, and SEC, specify requirements for data retention and recoverability. In meeting these requirements, businesses have to deal with a variety of risks to data including inadvertently deleted files or records (operator error), viruses or hackers that can cause data corruption or deletion, and natural disasters that may put much more than just your data at risk. Distributed or branch offices may also have ease of use requirements that may not apply to larger, more centralized businesses.
Do you have a plan that meets your recovery requirements to your satisfaction across these areas?
Issues with Legacy Recovery Technologies
If you are like most businesses, you are using some form of data protection today – probably tape-based backup. Periodically, someone shuts applications down to perform a backup to tape. Depending on the volume of data that is being copied, this may take several hours and requires manual intervention to set up the backup job, run it, confirm that it occurred, and then return the application to operation. The backup copy may be kept locally in case data needs to be recovered in the near term, and eventually (after several weeks) it may be moved to an offsite location for archival storage purposes. The reason to make and keep copies of your data is so that, in the event of some sort of event or catastrophe that deletes or destroys data, you have a clean copy safely tucked away to use for recovery purposes.
Tape is used for backup and archive because it is very inexpensive, but it is an old technology that has been available almost since the dawn of computing. There are several issues with tape-based backup:
- Tape-based backup is a time-intensive process that is potentially disruptive to your applications; this issue is commonly referred to as the backup window problem.
- Because of its impact on applications and resources, tape-based backups are usually not taken more than once a day, and often only once every several days, meaning that there are very few tape-based recovery points available for use over the course of a week; this is problematic because your data is changing very frequently (on the order of seconds or minutes) and the fewer points in time you have a copy of (for recovery purposes) the more data loss on average occurs for a given recovery; this issue is commonly referred to as the recovery point objective (RPO) problem.
- Once it's clear that a recovery needs to occur, it takes time to perform the recovery (e.g. finding the right tape, transporting it (if it's offsite), restoring it to disk, restarting the application on top of the data, etc.). This issue is commonly referred to as the recovery-time objective (RTO) problem.
- As a storage medium for backup, tape is not entirely reliable; in fact, leading analyst groups such as the Gartner Group, the Enterprise Strategy Group, and the Taneja Group state that as many as one in four backup tapes suffer from some sort of problem that precludes performing a recovery.
Transporting tapes to offsite facilities for archival purposes also has inherent risks. Widely publicized tape losses during physical transport (by truck) have hit large companies like Bank of America, Citigroup Inc., ChoicePoint, Inc. and LexisNexis and resulted in the theft of hundreds of thousands of company records. Replication of data across secure IP-based networks is a much faster, easier, and safer way to transport data to offsite locations for archival storage purposes. If you are driven by either business or regulatory requirements to deploy a disaster recovery solution, a pure tape-based data protection strategy can subject you to undue risk.
In evaluating solutions, determine if the product has the following features:
- Backup window: Data is continuously and transparently copied from designated servers throughout the day as changes occur, so you never again have to concern yourself with backup windows.
- Recovery Point Objective: Using technologies, such as “continuous data protection” (CDP), the product will allow you to retroactively pick any previous point and generate a readable, writable snapshot of what the data looked like at the selected point; this effectively presents you with all possible recovery points to minimize data loss on recovery in a way that tape, with its limited number of recovery points, never can.
- Recovery Time Objective: The product restores directly from disk, providing you with fast, reliable restores in a way that tape cannot. And your ability to pick the optimal recovery point to minimize data loss means that you will spend less time restoring the entire application environment; this effectively shortens the downtime associated with data recovery and hence the impact and cost of an outage.
- Redundant Application Server: The backup server provides a manual failover target that will allow a critical application to be rapidly restarted with access to current data (to allow processing to continue if the primary server for some reason cannot be restarted).
- Remote replication: The product includes the ability to replicate data across IP networks so you can migrate your aged data to a remote facility without exposing it to the risks associated with the physical transport of tape-based media.
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