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Fail safe
Disaster recovery tools help agencies replicate the systems they need to survive a major outage
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Disaster recovery tools
RFP CHECKLIST: Disaster Recovery
Define your end, not means. For example, specify that if your production site goes down, you want an alternate application service and all associated data to be available within 12 hours, with no more than an hour of lost data.
If one of your critical applications is a database, ask whether the DR system covers all transaction types, including insert, update and delete.
Ask what the system does to mitigate the risk of tape or hard-drive backup failure.
Beware version creep. Spell out the current versions of the applications you need to run and inquire about the process for handling updates.
Gauge replication performance carefully. Some vendors might only provide numbers for asynchronous replication, which is typically faster than synchronous. Ask for throughput rates that reflect peak demand periods, not just averages.
Find out how seamless failover appears to users. Are they disconnected from the network? Will they have to log in again?
Know the difference between failover times for disaster recovery and high-availability situations. The latter tend to be quicker, but do not reflect real DR environments.
If vendor consolidation is a goal in your enterprise framework strategy, look for vendors with the most complete DR suite that, at minimum, includes a variety of backup tools, replication and continuous data protection.
Watch for compatibility with your existing server and storage platforms. Many DR vendors support a variety of hardware brands and operating systems, but some only support a single OS, such as Windows, or their own storage arrays.
Investigate a replication program’s failback process, where it returns control to the primary site after failover. Many products do it manually, while a few are automatic.
Beware of vendors who claim certification from your server manufacturer, but only have it for one or two of their DR tools.
Remember that the people expected to run the remote site might be inexperienced. Documentation and training are critical.
The technologies for keeping systems online in a catastrophe are essentially the same as for maintaining redundant servers, applications and databases for high availability. But dispersing systems geographically so resources stay online when disaster strikes offers a new wrinkle and a fresh set of IT challenges. Challenges that experts say agencies can and should overcome.
“Do something,” said Steve Duplessie, senior analyst at Milford, Mass.-based Enterprise Strategy Group. “It’s too cheap and too easy not to start moving data off-site.”
Three pillars of DR
The technologies behind disaster recovery fall into three general areas: backup-and-restore, replication and failover. How an agency approaches those areas and the infrastructure it eventually deploys depend on how it chooses to characterize “disaster recovery,” based on the agency’s unique mission.
Two common DR benchmarks are recovery point objective and recovery time objective. RPO gets at the issue of acceptable data loss from a failure. If a system goes down, is it acceptable for you to bring it back online with month-old or week-old data? RTO, on the other hand, is about availability: How quickly does a system need to be back up and running?
Having identified their systems and spelled out RPO and RTP requirements, agencies can started to solicit products that meet those requirements.
At their most basic level, all disaster recovery solutions include a backup-and-restore infrastructure. In fact, much of today’s DR technology debate echoes the thinking behind storage management evolution over the past decade. Agencies that need data backups in case of emergency must weigh the price/performance differences among storage media such as optical tape and, increasingly, cheap Serial ATA hard drives that could function as virtual tape drives. Agencies must consider how these technologies fit into a cost-effective DR strategy while solving their recovery point and time objectives.
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