Thanks for the reply!
By load/unload do you mean simply inserting a tape cartidge into the drive, then ejecting it? I've done that dozens of times, and have probably written at least 10-15 tapes since this problem began. I've used 4 different tapes while attempting to diagnose this problem, loading/unloading/writing/erasing/rewriting etc. It takes at least 10 hours to create each backup tape, so the drive has been run enough to safely say I've already unwittingly applied your suggestion. The only thing I haven't done is use a cleaning cartidge, but I've certainly run more than a few passes with a new tape.
Generally I don't use the load command($ mt -f /dev/st0 load), I just gently push the tape into the drive until it grabs hold of the tape and does the rest. Does using the command actually do anything? The drive sounds like it goes through the same operations irregardless of whether I use the command or nudge it in manually. The script which writes the data to the tape ejects it when finished using ($ mt -f /dev/st0 eject).
I'm not quite sure why the log shows very few load/unload cycles, unless I completely misunderstood what you said (I think I'm correct, as the mt manual page uses 'load' in the same context).
I don't know when a cleaning tape was last used on this drive... It may have been awhile. I don't have any LTO-4 cleaning catridges, but I do have some LTO-1 cartidges. The directions on those say they're ok to use on LTO-2 but state nothing about LTO-4 which is why I haven't already used one. I assume this is because these cartridges were purchased before the existence of LTO-4 was publicly acknolwledged. The directions also say not to use the cartridge unless the cleaning light on the drive is illuminated, which hasn't happened.
Again, thanks for the help, any/all suggestions are welcome, I just want to resolve this issue!
