or, not all LTO media is created equal.
There’s an assumption that because LTO is a standard shared by multiple vendors, then any Ultrium media can be used in any Ultrium drives. (NB: Of course I’m referring here to the same version – i.e., version 4 media in a version 4 drive, or version 3 media in a version 3 drive, etc.*)
While technically this should be true, in practice it usually isn’t. I don’t wish to name vendors here, but suffice to say that I’ve had real-world experience, both in implementation and support scenarios, where tape drives have come from vendor A, but media was purchased from vendor B due to cheaper prices, and there’s been no end of “fun”. (That’s for very small values of “fun”, as a one-time colleague of mine used to say.)
When this has happened it’s usually manifested in one of a few different ways:
- Excessive numbers of media failures – e.g., hard errors.
- High numbers of tapes filling before they should – e.g., a 400GB tape filling at 300GB, 250GB, etc.
- Significant slow-downs accompanied by SCSI warnings.
In such cases after all other possibilities have been eliminated – hardware, software, firmware, operational handling, etc. – these sorts of problems have been eliminated by changing media. I should note that in such situations, I’ve had customers actually send their media back to whom they purchased it from, who tested it, and certified it as being 100% OK. OK in different drives, that is.
This is not a posting recommending that you always buy media from whatever vendor your tape drives came from. I would however suggest the following:
- Media that comes from the same manufacturer as your tape drive vendor will be OK.
- Media that comes from reputable media vendors that don’t make competing tape drives should also be OK.
- If one vendor’s media is ridiculously cheap – e.g., half the price from one vendor than it is from all others, then maybe you should exercise caution before committing your backups to it.
- Any decent media supplier will be able to tell you which media is recommended for use with a particular vendors’ tape drives.
- Most hardware vendors do actually, if you look closely enough, recommend particular media vendors. This will undoubtedly include their own, but it usually includes 2 or 3 others. You should trust that information.
—
* I haven’t forgotten about backwards compatibility of media – e.g., any LTO-x drive must be able to read x-2 media and write x-1 media in addition to x media.