For years now, information technology professionals have championed the need for reliable backups, while cost-conscious managers cringe at the price tag. With the advent of cloud computing, the game has changed but the rules remain the same.
While most folks are familiar with the basic concepts and options for backups, many wrestle to find an appropriate solution. As with anything else, you get what you pay for. How, then, does a business or government agency determine the best way to ensure that they can recover from any unfortunate or unforeseen event?
Like many problems in the IT world, we solve this one with a couple of acronyms, RPO and RTO. RPO stands for Recovery Point Objective, and is that point in time to which you can effectively restore your data. Typically, this will be the date and time of your last good backup.
RTO, or Recovery Time Objective, is the amount of time an organization can be without its system(s). RTO obviously affects the methods and technologies used to conduct system backups and subsequent restores. If your RTO is 12 hours, your backup needs to be in a format and a medium that can be restored in that time frame. Realistically, though, it should be restorable in half that time frame, to allow for any hiccups that might occur during the restoral process.
Organizations should first measure their RPO and RTO before deciding on a backup method. Being able to restore from data that is hours or even minutes old (shorter RPO) will cost more. Similarly, the quicker your system needs to be up and running (lower RTO), the higher the cost. Of course, many organizations adjust their objectives once cost is fully defined.
Given these parameters, then, it is sometimes easy to rule out certain technologies. For example, a cloud-based backup, while typically less inexpensive, suffers from a long RTO. After all, restoring hundreds of gigabytes or even terabytes over your average Internet connection is going to take a while. If your data set is small, then a cloud-based solution might be more suitable.
One of the benefits of most cloud-based backups is that they are always on. So your data is always being backed up, and your RPO is very low. Disk-to-disk backups also can provide a very low RPO. Old-fashioned tape drives are still popular in larger organizations, despite their relatively lengthy RPO. This is largely due to cost, as tapes are still much less expensive than disks.
Another benefit to cloud-based backups is their inherent nature of being off-site. On-site backups to tape or disk still should be taken off premises to add another layer of safeguarding.
A hybrid approach is becoming more and more popular. Cloud-based backups are used for day-to-day data recovery use, while disk or tape backups are used in case of outright disaster.
Of course, organizations need to test their backup strategies regularly. It’s not enough to just make sure the backups run; you need to test the restore process as well. After all, an old joke in information technology is that backups always work, but the restores are what give you a hard time.
John Agsalud is an IT expert with more than 25 years of information technology experience. Reach him at johnagsalud@yahoo.com.
