While backup of electronic data is a critical part of the disaster recovery (DR) equation, more attention is often placed on the backup piece than the recovery piece. There are three requirements for DR data protection:
- It must be sufficiently current to meet the requirements of the recovery point objective (RPO) for the system.
- It must be capable of being re-loaded within the recovery time objective (RTO) governing the target system and its data.
- It must be stored in a secure location sufficiently distant from the location of the primary data that it is not likely to be affected by the same interruption event.
The magnetic tape solution
Tape backups are still the most common data backup technique, used since the earliest days of commercial computing. There have always been problems with tape backup, but for a long time, it was the only viable choice for backup.
First and foremost, tape is fragile. In January 1995, Scientific American published an article called "Ensuring the Longevity of Digital Documents," where the physical lifetime of magnetic tape was estimated at 1 year. Too many writes, poor conditions for media storage or transport and an ever-increasing density since the time this article was written can all contribute to increasing read or write errors that can reduce media life to even less than one year. Manual intervention is necessary to verify that backup jobs have completed successfully – and of course this is not always done.
But perhaps the largest drawback to traditional tape backup was the "elastic" RTO and RPO. Once-a-day writing of tape backups is the only feasible possibility, given requirements to actually use the data, and this inevitably resulted in lost transactions and often an inability to meet both the RTO as well as the RPO (which was often listed as "last cycle," but even this was rarely met). Many firms are still doing ineffective tape backups, not realizing that e-vaulting solutions have become quite cost-competitive.
The e-vaulting alternative
E-vaulting technologies are very different from tape backup procedures. There is no daily or cyclical creation of backup tape volumes. All systems work more or less like the following, with variations to meet specific client requirements:
The vendor installs software at the primary site and assists the staff in configuring it. Reports may be run for a period of time to detect when and where changes occur. Deduplication may be used to decrease the amount of data being backed up. All of this helps to "tune" the backup requirements.
A "seed" or one-time copy of all data to be vaulted is made and communicated (or physically sent) to the vaulting site at the remote location (internal or external) .
The changes detected by the e-vaulting agent at the defined intervals are then copied and communicated to the e-vault. These intervals can vary for difference sets of data, and can come close to supporting an RPO of point-of-failure, with very aggressive RTO's.
Note that e-vaulting is NOT the same thing as failover to a "live" system maintained in a mirrored state with the primary system. There is no reserve or "live" backup hardware configured with the application systems that use this data in a pure e-vaulting solution. Time will still be required to connect the backup data to a server running the application software that uses this data.
E-vaulting services are now available from a number of third-party firms, many of which have a long track record. All of the primary US recovery site providers, SunGard Data Systems Inc., IBM Corp. and Hewlett-Packard (HP) Co., offer e-vaulting services, as do many regional recovery site providers. A number of reputable e-vaulting-only commercial firms are also available. If you work for a company with a very large systems environment, you are probably already running e-vaulting services internally, (along with high-availability remote mirroring operations for your largest and most critical databases). Small and medium-size firms can choose from a variety of commercial e-vaulting services to meet their particular needs.
If you are now evaluating e-vaulting as a solution for your DR needs, consider the following steps:
Collect ALL costs associated with your current tape backup solution for the past year. This will give you a basis for cost comparison. Include the following:
- Cost of media for one year
- Cost of hardware (including operating system and power if possible)
- Staff costs for one year (do not forget to factor in benefits)
- Tape pickup and delivery costs for the past year
- Storage costs for the past year.
Define your requirements. Are some of your databases really candidates for failover remote-mirrored solutions? Email can be a particularly demanding case, and there are many specific solutions that provide Outlook or other email application backup and failover (including failback). Check these for your email requirements.
Define the RPO (currency of data backup up to near-point-of-failure) for EACH of the sets of data you will be backing up.
Define the RTO when the system is up and running again with all of its data for EACH of the applications you will be backing up.
Ask around. See how other organizations in your space are dealing with e-vaulting.
Write down what you are looking to accomplish via e-vaulting, including your RPOs and RTOs, and your data and system configuration. Send this to all the vendors you believe may be qualified.
After holding preliminary discussions with vendors, talk to a few of their customers.
Analyze the costs and benefits from each; select your top three and ask them to submit written proposals that address your requirements – OR – you may need to do an RFP, depending on your organization.
Compare the costs and benefits of the proposals you receive with those from your current tape solution.
As with any change of technology, there will be a few bumps along the way, but these should be worked out quickly. As major changes go, this one should be relatively pain-free. And the result will be worth it: your final e-vaulting solution will provide clearly better reliability and much greater flexibility than any tape-based backup solution. No matter what your data backup needs, you should be able to find an e-vaulting solution that scales either up or down to meet your individual requirements with costs that may be a pleasant surprise.
Remember that the shelf life of disk media is about five years as compared to one year or less for tape media. And if you need to hold archive data for more than five years, consider paper, microform or optical media.
Kathleen Lucey, FBCI, is the president of Montague Risk Management and is president of the Business Continuity Institute USA Chapter.
