Backup vs. DR: Just because you backed up your data doesn’t mean you are ready for a disaster!
In various conversations I have had recently, and even in the press, there seems to be a common misconception that if you backup your data you are ready for a disaster. There are situations in which this is the case but with the emergence of disk-based backup often this is no longer true. Knowing whether or not you are ready for a disaster is a matter of examining where your data resides.
Why is location so important?
Providing a safe location to store your data once it has been backed up is arguably as important, if not more so, than doing the backup itself. After all, if you backup your data but can’t get it back you might as well not have backed up in the first place. Now, in terms of what constitutes a safe place for your data is really up to each individual to determine. However, there is one key question that everyone should ask:
If a fire, flood or other cataclysmic event occurred wiping out the source of my data is my backup in a different location?
And, this is why location is of such importance. Just because you have backed up your data does not mean that in the event of a true disaster (not just a personal disaster in the sense of “I’ve lost my PowerPoint presentation and I only have 5 minutes until the big presentation”) you will be able to recover unless you have taken note of the location issue. This is also why disk-based backup, for all of its merits of improved backup performance and quicker restore times, is not disaster recovery compliant (at least not if you agree with the statement regarding location). That is not to say that disk-based backup can’t work. Rather, it suggests that if you are going to rely on disk-based backups you may need to consider data replication technologies that will allow you to create a copy of that data on another disk system in another location. Of course, this is probably going to be quite a costly approach not only from the hardware perspective but also taking into consideration power, cooling, floor space, etc. Another option, albeit seemingly passe these days would be to use tape.
Tape, unlike disk (and I am excluding SSD for the time being), is portable. Given this, when you complete a backup to a tape cartridge you can take it to another site thereby satisfying the question of location. Tape, then, becomes one of the simplest ways of being able to legitimately claim that by simply backing up your data you are ready for disaster recovery. And, it’s cheap. Some sources have cited tape-based backup solutions as being upwards of 23 times more cost effective than disk-based equivalents. This is not to say that tape does not have its issues since there is certainly many cases that can be made for the relative fragility of tape compared to disk. Yet, it should not be denied that tape does offer a shorter and more cost effective route to disaster recovery preparedness.
In the end, whether your preference is to use disk or tape backup (or a combination of both) never lose site of the fact that just because you have backed up your data doesn’t mean you a ready for a disaster. Only when you can lay your hands on the media that holds your data when the data source has been obliterated can you truly say you are prepared. If you keep that in mind when the time comes you will be ready.
July 21st, 2011 by cyoung
Comments (1)
As cost effective as tape is in some cases disk can offer increased usability of the backup of data to tape.
For Business continuance supply of backed data from alternate locations can come from many sources including tape restore.
On some levels backups and archives are not as valuable as the day to day exercise of alternating the location that data is offered from leaving backups for just point and time protection and recovery from user errors.