SAN Backup Strategies

With SAN (or NAS) based architecture, tape backups can be extra challenging due to the sheer amount of data involved. What are the options and recommended strategies?

The unfortunate truth is that, unless you have the type of budget that allows you to have an off-site SAN as a backup host, tapes are still a fact of life. Though SAN storage is very robust, the non-portable nature of their disks makes it impractical to meet off-site storage requirements for disaster recovery purposes if you only have one SAN. While simply taking hot-swappable SATA drives off-site might be a cheaper alternative to a secondary SAN, they’re still larger, heavier, more expensive, and use more power than tape. Likewise, though solid-state drives are lighter than SATA and require less power, they are even more pricey.

Still, you can minimize the amount of data you have to back up and the number of times you have to do it. This is particularly true of virtual servers. For instance, not much changes on a web server once it has been configured, so don’t waste your time backing it up every night or even every week. Save it for a monthly backup after the latest round of patches has been installed.

For servers that are more volatile when it comes to file changes, there’s still little reason to back up all of the static operating system files for each server repeatedly. With a standardized virtual server image that you’ve already backed up, you can save time and space by only backing up the post-configuration data files and folders that change with a server-level backup application.

As is always the case with backup strategies, ease of use during the backup process comes at the cost of more effort during the recovery process, so weigh your options carefully. For more tips on creating an overall backup strategy, read last year’s article on Backup Strategies.