The drumbeat is being heard. A recent survey commissioned by Permabit Technology generated some interesting results. While almost every answer creates interesting blog material, the stats that jumped out at me were that almost 25% of those surveyed are managing more than 100 TB of primary storage and that 43% of those surveyed were paying $25 to $40-plus per gigabyte for that primary storage. These stats make it quite clear -- you can't afford not to archive data.If those companies with 100 TB of data are paying near the low end of that cost per gigabyte price, or $25,000 per terabyte, that means at 100 TB they have $2.5 million invested in primary storage. That's using today's pricing; you probably paid a lot more than that a few years ago.

From other studies, surveys, and conversations with customers, we know a couple very common truths. First, about 80% of primary storage is inactive, and second, if you have 100 TB now and don't do anything about it, you're going to have 200 TB in very short order. In fact, many of these companies probably have purchase orders already being processed for more storage.

For example, let's say in the next year you had to purchase another 25 TB of storage at the above price of $25 per gigabyte. Instead of buying that 25 TB, what if you moved it to a disk archive? A net new purchase of 25 TB of Tier One primary storage at $25 per gigabyte would cost $625,000. By comparison, even using the upper range cost of disk-based archive, per-gigabyte pricing ($5 per gigabyte) would cost about $125,000 for 25 TB. Moving this stale data to a disk-based archive instead of buying more primary storage would save you $500,000 in year one. Think you can get new primary storage cheaper? Cut the price in half ($312,000, or $12.50 per gigabyte). You still save more than $187,000. We have done a lot of server virtualization rollout projects and none of them has come close to that number as a year-one ROI result. In short, do you need to cut money out of your IT budget right now? Forget about virtualization -- archive. Don't have 100 TB? The math is linear: 50 TB, an ROI of almost $94,000, still a good thing. The impact of a disk archive is more than just delaying a primary disk purchase. There also is a reduction of the backup resources needed to protect that data, the resources needed to replicate that data, and the resources needed to manage that data. Not to mention any downtime that may be associated with implementing the new storage system and migrating data to it. Add to all of this the fact that almost every organization is going to need to be concerned about data retention in the coming years and disk archiving lays the foundation for that initiative as well.

George Crump is founder of Storage Switzerland, an analyst firm focused on the virtualization and storage marketplaces. It provides strategic consulting and analysis to storage users, suppliers, and integrators. An industry veteran of more than 25 years, Crump has held engineering and sales positions at various IT industry manufacturers and integrators. Prior to Storage Switzerland, he was CTO at one of the nation's largest integrators.