One of the many promised benefits of the cloud is the availability of cheap, unlimited storage. From a disaster recovery and business continuity perspective, virtualized storage of vital data is truly revolutionary, as it allows organizations to realize more affordable and more efficient backup strategies.
Before the cloud, companies and many organizations used tapes to back up data on a weekly basis, with daily incremental backups to capture changes, and then rotated those copies through physical off-site storage.
In case of disaster, the appropriate tapes would be retrieved and delivered by truck to a disaster recovery facility, where the backed up data would be copied from them into an exact duplicate of the production data center infrastructure. Completing this process could take a few days.
Disk backup systems provided a significant advance over tape, enabling more frequent snapshots of ongoing operations and much shorter recovery times. Under such continuous use, disks are also much more reliable than tape.
But disk storage systems, in particular high-end storage area networks required by the largest organizations, can be costly. And they are not portable like tape, requiring some other method of replicating backed-up data to an offsite location.
This obstacle was overcome through the combination of several enabling technologies.
First was advanced deduplication and compression that reduced the backup footprint, helping to contain storage hardware requirements.
Next was the availability of high bandwidth networks that increased the practicality of transmitting these compressed backup files to remote backup facilities or service providers.
Finally, virtualization eliminated the need and cost to exactly replicate production data center hardware at the disaster recovery facility.
Organizations can now meet their backup and recovery requirements in a variety of physical-to-virtual, virtual-to-virtual, virtual-to-physical and traditional physical-to-physical configurations.
Cloud storage is the next step in this evolution. As commonly understood, it means transferring data over a network to an off-site storage system maintained by a third party rather than storing it on tape or disk. Storing data in the cloud makes it easier and faster to retrieve than from tape or disk backup.
Cloud backup and recovery provides same-day recovery, restoring business operations in hours as opposed to days or even weeks, with as little as 15 minutes of data loss and at a lower cost than tape-based processes.
For these reasons, cloud backup is a natural fit for disaster recovery strategies. But two high-profile mistakes last year show that cloud based storage still has some risk attached to it.
In February 2011, Google’s update of storage software hit a glitch, which emptied over 150,000 user accounts and rendered Google’s redundant cloud-based copies unavailable. Google was eventually able to restore this data from offline tape backups.
Clients of Amazon EC2 cloud services were not so lucky when a network change in April 2011 led to a failure that disabled some high-profile sites for days and left many customers with permanent data loss. Since tape is not mentioned in any media coverage of the failure, one can only assume that the same type of tape backup that saved Google customers’ data was not available at Amazon.
For this reason, tape and disk backups are still viable — even necessary — parts of any disaster recovery / business continuity plan.
While these options — particularly tape — cannot match cloud storage for speed and ease of use, they offer a much needed insurance policy in case something goes awry, as in the case of Google and Amazon.
Replication of backed up data to redundant, mirrored physical or virtual storage systems is a disaster recovery best practice — but only if the multiple backups are themselves not vulnerable to the same threat. As unlikely as the simultaneous failure of all backups may be, one important role for tape in the era of the cloud is to be the ultimate backup for data that resides in the ether.
The inclusion of tape and/or disk storage in a disaster recovery strategy is often called a hybrid solution. This allows users to take advantage of the affordability and efficiency of cloud backup while still insuring against the ultimate disaster: the complete loss of vital data.
Does this mean that cloud storage is all hype?
Not at all. Cloud recovery services are making it easier to attain professional-level services at a reasonable cost with reduced effort or expertise on the customer’s part. Technologies such as VMware and backup deduplication have enabled the disaster recovery industry to offer cloud services.
The year ahead will see a major increase in cloud based recovery services as more companies seek to eliminate the need to use tape-based restores as their primary method of data recovery.
Though relatively new, cloud recovery can result in improved recovery point objectives and recovery time objectives when compared with conventional tape-based strategies. In addition, cloud recovery greatly improves the efficiency of customer recovery processes during tests and actual disaster events.
But tape still plays a role as secure offline storage in a hybrid backup and recovery solution that combines on-site disk backup, physical or virtual cloud-based storage and tape.
Dick Fordham is director of corporate strategy for Recovery Point, which provides disaster recovery services.