Whenever you go to the store and purchase a good, the employee at the checkout stand scans a small portion of the item with a scanner. That little portion of the item they scanned, also known as a Universal Product Code (UPC), holds all the information needed to complete your purchase such as SKU number, price, and inventory adjustment. A UPC, or barcode in other instances, is simply a method of representing data in a visual, machine-readable form. Almost everything has a barcode, even data storage devices that store the information on the barcodes themselves. It’s really a complete circle when you think about it.
If you’re familiar with the data storage landscape, you’ve more than likely head of VOLSER barcode labeling. VOLSER is a more efficient way of saying volume serial number, which is a serial number assigned to a disk or tape storage format. Originating in the 1950s in mainframe computer operating systems, the VOLSER bar code labels on data tape storage cartridges provide both human-readable and machine-readable identifiers, allowing tape libraries to correctly manage the tape cartridges stored inside them. The VOLSER label is a feature used to verify if the storage medium is in the correct drive and identify if it was replaced with another one.
How do barcode labels work in tape libraries?
Barcode labels are what allow tape drives and tape libraries to properly read the data off of the tapes themselves. It’s a very intricate and calculated process that takes place. The bar code labels used with tape media use what is called Code 39 symbology. Code 39, often referred to as Code 3-of-9, consists of three wide elements and six narrow elements for every nine elements. The elements in reference can either be a black, non-reflective bar or a white reflective space. This unique format gives proof that a valid code is on the tape.
The Code 39 symbology method of barcoding uses a non-visible asterisk as the stop-and-start characters. A bar code reader can find the start character and the stop character and determine the direction of the characters by analyzing the asterisks relative to the lead-in white space on the label, ensuring that the tape is inserted in the right way. With tape libraries and tape autoloaders, the barcode reader is at a stable distance and angle from the VOLSER label. With the barcode reader in a fixed position, it is vital that the tape’s VOLSER label remain clean.
Once the barcode reader gathers the information needed from the VOLSER label, the tape is loaded and unloaded from the slots to the tape drive for the read/write process. LTO tape labels include human and machine-readable components for automation, whereas standalone drives don’t, and labels are not required.
What type of information is on the barcode label?
An LTO tape media or LTO cleaner tape that is used with an autoloader or a library requires an LTO Label for identification. The label consists of two parts:
The VOLSER number is human-readable with the first 3 places occupied by alphabets characters and followed by numbers.
Tape Media Generation
The last 2 digits of the barcode are a machine-readable media identifier and that must correspond to the type of storage media being used. The media identifier for each kind of storage media can't be changed as it is fixed for the generation.
The following are also parts of the barcode but can be customized for any organization.
- Colors can be personalized as standard colors, colors based on position, or colors based on the content of the storage media.
- Barcode orientation can be modified to be on top, bottom, or rotated.
When read by the library's bar code reader, the barcode identifies the cartridge's VOLSER to the tape library. The barcode also tells the library whether the cartridge is a data, cleaning, or diagnostic cartridge.
Benefits of VOLSER barcoding
Using VOLSER barcode labels on tape media cartridges can significantly improve the efficiency of a tape management system. Using the barcode information to track the cartridges within the library and outside the library has numerous benefits. Not only do the barcodes allow for ease of organization and identification both in and out of the tape library, but it allows for increased data security when transporting tape media to an off-site location. Scanning the barcodes ensures all tapes are accounted for at the end of the day. Just by taking a few simple steps, a data manager can recognize the advantages of the system.