On Apr 24, 2014, at 6:17 PM, Prather, Wanda <[email protected]> wrote:
> My thoughts too! > HOW can that happen in a VTL? Unless there is real physical damage? > I'd sure check the back end for any warning lights/alerts/logs. It happens. In a recent life, using two different technologies from one vendor, we saw it with some regularity. The older technology simply wasn’t stable in the configuration we were using (*cough*3D4000*cough*), and VTL crashes would leave unusable tapes. The replacement technology, still in wide use, was much more stable, and I’m not as certain that we had any corruption issues with those, but I have a nagging feeling there was a problem when TSM would dismount a tape and then remount it quickly. Sadly, it’s been almost nine months since I last worked with those VTLs, and I don’t remember the oddball failure modes that we shouldn’t have been seeing but vaguely were. I loved those VTLs, and I’d happily use them again, but we had enough of them and used them enough that we saw a few weird glitches that we could’t pin down but were uneasily aware of. It was a very, very low failure rate, but it wasn’t zero. Bottom line? You really need to use copy pools, even if your VTLs replicate. I haven’t used all of the VTL technologies out there, but since it’s all virtualized, not physical, there are some odd failure modes that real reels (cartridges) simply don’t have. It will vary from type to type, but it’s all done with software, and no software is perfect. Diversity in your backups is crucial. Says me. I, too, am prone to the odd failure mode. Nick
