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. DISASTER/OFF-SITE   BACKUP Have you ever given any thought to how much time and money are invested in the library? If you are not working in the library at the moment, next time you visit one, look around and try to imagine how much money it would take to replace the equipment and the media, and how   much   time   it   would   take   to   recreate   all   the necessary files if everything were totally lost because of fire or flooding. Depending on the size of the library and the types of media it contained, it could run into the millions  of  dollars.  Remember,  data  entry  personnel  do not work for nothing. The loss of these media can have harmful effects on your command’s operations for quite some time. And, as we have already noted, recreation of files  can  be  extremely  costly. All systems software, master files, and other critical entries  and  documentation  should  be  duplicated  as backup on a regularly scheduled basis and stored in a protected area, as far away from the library as possible. In spite of the many precautions that can be taken to protect  the  security  of  the  computer  center  and  the media library, the safest possible means of protecting data  and  information  of  a  vital  nature  is  the  off-site, back-up  procedure. This  is  true  because  there  is  no totally fail-safe procedure to protect a computer room or the   library   from   the   many   dangers   to   which   it   is exposed. 2-13