Say, What?

In my last column, I responded to a question about how to archive all of this data we’re capturing and brought up LTO. As promised, here’s a little more about the flavors of LTO.

Prior to LTO, archiving technology was spread across a number of competing and proprietary systems. Many of you have heard of DLT. This is a tape-based system, which is used for both archiving and delivery of assets. For example, DLTs can be used to deliver DVD projects to replicators. (In the early days of DVD, that was the only way to do it.)

The problem with these formats is that a single company controls them. They control who can build drives and who can produce media. This can lead to higher-priced equipment and tapes since there isn’t much competitive pricing pressure.

A few technology companies saw an opportunity and decided to form a consortium that would develop an open standards-based tape format. The "O" in LTO stands for "open." These companies developed a standard that would provide users with multiple sources for drives and media.

One of the most important results of that consortium is a road map. Since archiving is all about long-term storage of media, it’s important that you "place your bet" on the right technology. I use the gambling metaphor because with storage technology, it’s difficult to predict the future. For example, with DLT, there was a DLT I, DLT II, DLT III and DLT IV, but how those variations worked and how much they would store wasn’t laid out ahead of time.

With LTO, the consortium provided a published road map that shows generations of LTO all the way up to LTO-8. Late last year, the first products using LTO-6 started shipping. Beyond a road map, LTO provides a version compatibility standard. Since we’re talking about archiving over the years, it’s nice to know which version of the format will play, in which drive. LTO backward compatibility is straightforward: An LTO drive can read data from the previous two generations of LTO tapes. That’s only for reading; for writing, it can go back one generation. For example, if you have an LTO-5 drive, it can read LTO-3, LTO-4 and, of course, LTO-5 tapes. It can write to both LTO-4 and LTO-5 tapes.

Why would you write to an LTO-4 if you had an LTO-5 drive? Well, you might if you wanted to add to an archive. Let’s say you archived a whole show—including footage and project files—to an LTO-4 drive a few years ago. Now you restore it and make a slight change. When you archive it again, you might only have a small file to add to the archive, so it makes sense to keep it all together on the LTO-4.