NONPERMANENT LABELS.\ The non-permanent type label has a special adhesive backing of stick-on-type construction that can be applied to just about any kind of surface yet be removed with very little effort. This type of label is most useful in applications where information regarding the media itself, or what is written upon it, changes quite frequently. Usage labels, cleaning labels, and save labels are usually nonpermanent type labels.

Usage Label. \ The usage label is used to determine how many times a tape has been read from or written to. It can be placed on either side of the tape reel. The usage label is normally made up of several boxes or circles (approximately one-quarter inch in diameter), which are filled in (one at a time) by the computer operator each time a tape is used. Notice that we did not mention disks. Disks are normally sent outside of the command for cleaning. At that time, they are also certified for use. However, magnetic tape is an entirely different story. After so many uses a tape must undergo

2-12 a cleaning, and that is where you come in. Every time a tape is returned to the library, you should make it a point to check the usage label to see whether or not it requires cleaning. A magnetic tape maybe cleaned at any time. However, if the tape does contain live data (data still needed), try to be extra careful not to damage the tape during the cleaning process. Normal operating conditions in the computer room require the read/write heads to be cleaned at least once every 4 hours of operation and the entire unit once every 8 hours unless usage is very heavy or as specified in the SOP. If this is done, a tape should be cleaned after every 5 uses, and the number of uses between cleanings should never exceed 10.

Cleaning Label.\ The cleaning label is used to indicate when and how often a tape has been cleaned. This is important to know, for after a tape has undergone so many cleanings (usually 10), it should be put through a certification process to determine its accuracy (reading and writing capability). Normally, you place the cleaning label on the backside of the tape, since the information it contains is useful only to you, the librarian.

Save Label.\ Whenever a tape is to be saved for a period of time, a save label, such as the one shown in figure 2-6, is required for accountability. The save label (also referred to as a user label) contains information that helps to identify the job/task number and the data file(s) written on the media, along with other related information. This label is placed on the front side of the media so it can be readily seen by all. Each individual programmer, user, and, in some cases, the control clerk (depending upon command policy) has responsibility for filling out as much information on the save label as possible before job submission. He or she normally enters such information as: job or task number, file identification, security classification, purge date, and/or its period of retention (30,60, or 90 days). When the job

Figure 2-6.\Magnetic tape save label for unclassified (UNCLAS), Privacy Act (PRIV), and For Official Use Only (FOUO).

is run, the operator inserts the remaining entries: reel sequence number(s), the creation date of the file, the system on which the job was run, the magnetic tape unit (the drive #) that was used to create the tape, along with his or her operator number or initials upon completion of the job. These newly created tapes are then forwarded to the library, where you (the librarian) check to see that all required entries on the save label have been made. If there are discrepancies, it is your responsibility to notify the appropriate personnel so that corrective action may be taken. Once you are satisfied that all label entries are correct and complete, you can then proceed to log and file (store) the media for future use.

Whenever you are asked to pull (retrieve) magnetic media (input tapes, disks, diskettes), you should ensure that save labels accompany the job request for all outputs to be saved. Do this before releasing the job to the computer operator.

Internal Labels

Before releasing new magnetic media from the library, you are sometimes required to put the media through what is called an internal labeling or initialization process. As the librarian, one of your many jobs may be to perform this labeling or initialization process. Why? you might ask. Good question. Some computer systems require an internal label of some sort to be physically written on the magnetic media for validation (checking) purposes before the media can be accepted and processed by the system software and applications programs of the computer.

When dealing with magnetic tape, the internal label consists of two blocks of information written immediately after the BOT marker. The first block is normally reserved for the identification number, which is assigned by you at the time a new tape is added to the library. This identification number never changes. The second block identifies the information to be stored on the tape, along with the file ID. It may also contain date information that is used by special programs to further identify the tape and to protect the information from being destroyed prematurely. This type of information is normally provided by the programmer. You must schedule computer processing time to set up the internal label.

Like magnetic tape, whenever you introduce anew disk or diskette into the system, it, too, must undergo an internal labeling process known as initialization.

Initialization is somewhat similar to an initiation. If the disk pack (or diskette) passes a series of tests, then it gets to become a member of the library. If not, then the media is normally boxed up and shipped back to the manufacturer. To initialize a disk pack, you must have computer processing time at your disposal and a special program called a direct access storage device initialization (DASDI) program. The initialization procedure itself is designed to accomplish two things. First, during the DASDI procedure, an internal volume identification is recorded on track zero of the disk. Without this volume identification label, the computer cannot access the disk. Second, for a new pack, a surface analysis of the entire disk (or disk pack) is performed, defective tracks are flagged, and alternate tracks are assigned. In addition, a listing is produced that reflects the overall operating condition of the pack. This listing is normally retained in the library or in the technical support branch.

As you travel from one command to another, you will find that there are many DASDI programs available, under just as many names: INIT, FORMAT, and so on. The one you use will depend upon the system's hardware and its executive software.