The bar code label on a tape cartridge may be just a bit of paper, but it can still cause problems, especially in tape libraries, if a few simple precautions aren't followed.
An unreadable label makes the tape cartridge useless and a label that tears or comes off in the library can block scanners or even jam the mechanism. Hewlett-Packard offers several suggestions for dealing with tape labels.
Make sure of the label orientation and placement on the cartridge. The library expects to find the label positioned and oriented correctly. If it's not, it may slow down reading the label, or even make the label unintelligible to the library.
Use the right label. In addition to telling the library the tape number, the label also tells the library what kind of tape it is. Using a label, say, for an AIT tape on an LTO cartridge can make the library reject the tape, or even damage the tape or library when the library mechanism tries to put the tape in the wrong drive.
Don't put a new label over an old one when you re-use a cartridge. Remove the old label first. Don't tape labels onto cartridges. The tape can interfere with the library's scanner by changing the reflectance of the label.
Use labels and label stock within a year of purchase. HP says that once the labels are on the cartridges they will stay put, but the adhesive degrades while it is still on the backing sheet. After a year on the backing sheet, HP says, there is a chance the label will peel off the cartridge.
HP discusses labels in a recent white paper titled, "Bar code label requirements, compatibility and use."
Rick Cook has been writing about mass storage since the days when the term meant an 80K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last twenty years he has been a freelance writer specializing in storage and other computer issues.