LTFS: The Basics

A few weeks ago, I shared my thoughts on how LTO-5, in combination with LTFS, is changing the facts of life when it comes to tape. Given that our blog visitors tend to be fairly diverse in terms of industry, function and technical level, I thought it was worth a quick deep-dive into LTFS—what it is, what’s cool about it and why some say it helps tape act like disk. So here it is in a nutshell: your LTFS mini-primer.

What is LTFS?

LTFS (Linear Tape File System), created by IBM, is a self-describing tape file system. With LTFS software loaded, any computer can read any LTO-5 tape. With LTFS, you can see and manipulate files on tape just like you would if they were stored on disk or a thumb drive. LTFS lets you click, drag and drop to open, delete or modify files.

What’s the Big Deal?

These features of LTFS are a major step forward from the old days—pre-2010, that is—when you could access files on tape only in a linear sequence, and there was no directory or index, or sometimes even file names, on the tape to help you identify and locate files. Index data had to be stored in external databases that were part of proprietary backup software. Proprietary meant that you were locked in to your specific software and vendor since your software wasn’t interoperable with other systems, and also that you were kind of stuck—screwed, even—if your vendor went out of business and your software drivers went end-of-life.

LTFS’ capabilities mean two key improvements to this scenario:

• Tape can operate independently of the proprietary backup software used to create it—no worries about interoperability or your backup software vendor going out of business.
• You can access and modify files on tape using an easy file system interface, which makes the tape appear in the operating system just like any other drive—so tape is faster and easier to use.

These are some of the reasons why industry bloggers like W. Curtis Preston and George Crump have been lauding the praises of LTFS.

So there you have it—the “what” and the “so what?” of LTFS. What do you think about LTFS? Is this yet another reason to reconsider tape or do the benefits of disk make LTFS irrelevant?