So we have a long history of hating DLT drives here, beginning back before I had anything to do with backups when $COSA would get paged almost every night because of a jukebox failure (which boiled down to the op not closing the jukebox door) going on through 3 more generations of DLT technology (7k, 8k, and now SDLT600) It seems that DLT is keeping up with its heritage.
A previous DLT8000 library had lots of problems, which we theorized was because of dust & environmental contaminants, so we switched to Qualstar libraries. These have the best dust filters in the industry. For this particular replacement, we switched to LTO-2, and have had virtually no problems.
On the other hand, $THEY, when it came time to replace their aging DLT libraries (8k 2/20, 7k 4/48, 4k 2/28) decided that they didn't want to follow our success, but would rather venture off into the brave new world of SDLT. And since the SDLT600s were current, that's what they'd get (despite the fact that these are the only drives in the company that can read this media)
So that's the background... recently, I've had to kick this particular library at least twice per week, with other interventions required (not by me) probably more often. Sometimes the drive has the 3 blinking lights, sometimes not. Usually, the drive reports that there's no tape loaded. Sometimes the library agrees. Even more rarely, Networker agrees.
Sometimes pulling & reinstalling the drive fixes the problem. Today we had to unload the drive, reseat the drive, (watch Networker load a tape before we could stop it), try to unload the drive (it couldn't), reseat the drive, then got an error message of "logical unit communication failure". So we bounced the library, and now it's working (for now)
And of course, the web interface for this library is just barely functional, so in order to actually do anything, I have to walk to the datacenter. With $COSA following.
All this so that $COSA can dump 250GB of filer data off to tape before he deletes it.