Friday, August 14, 2009

In IT, in a rush to embrace what’s new and ‘sexy’ (in storage) I think we sometimes overlook what’s appropriate for the job - or for the application. This may sound quaint but sometimes tape is the appropriate tool for the job.

Disk backup is certainly here to stay, and it should be. Disk has replaced tape for a growing number of users and for others it makes tape backup better. But for a significant number of users, tape should be included in the backup mix, sometimes as the primary focus. What does tape bring to the party that disk cannot? 

Simple Recovery for a DR System

What happens when a disaster strikes and you have to recover some or all of your data that’s been replicated to a remote site? Maybe you used deduplication to reduce the bandwidth required. Do you restore the entire data set using these same pipes? Of course not - that would take forever. Most likely you would physically move the required copy of the data you lost on the array it lives on back to the primary site, or wherever you set up shop. How fun is that trip, moving a storage array in a truck across town or farther? Don’t forget, this may be your only copy of that data. Hopefully you made another copy before you left.

What if that copy was on tape? Hmm. What if you just put a copy of your data on tape in the DR site in the first place? Why not ship the tapes you need to the new site and restore those? I know, there are circumstances where a tape copy might not be the best answer, but for some users in some situations, tape is the best answer. As George discussed in his recent article "Integrating Deduplication" technology like Symantec’s NetBackup OST has the ability to write directly to tape from the disk backup appliance, putting this DR site data off to tape is simple; no need to run that copy back through the backup application first.

An Affordable Second Copy

Data protection is like insurance, it has an emotional component. It’s driven by fear - the fear of possible loss. In many cases the only way to deal with that fear is to make another copy of data. This can certainly be another deduplicated copy or an incremental copy made using a change-based technology, perhaps replicated to a remote location.

But, if you are resource constrained (sound familiar?) and can’t justify another disk appliance in a remote site, tape may be the right tool for the job. For ~$100 per TB and an autoloader, you can make that additional copy and put it anywhere.

But the point is, the appropriate technology for a given job may not always be the latest technology - even if you’re IN technology. Disk may eventually replace tape for most backups and continuous data protection may replace backups altogether. But for many organizations, at least in the mean time, tape is the right data protection tool for the job.

This strategy has a couple of other bonuses too. If it’s not the latest technology, it may be simpler and less expensive. This just means you don’t have to send everyone to training to implement it or pitch it to the CEO to fund it. Imagine that - you can get the job done, save time and save money too. Now wouldn’t that make Primitive Pete smile?

Eric Slack, Senior Analyst