Libraries

Definition

A library is a partitioned dataset--a file that can hold several other files. The file saved according to the instructions in Chapter 1 was a sequential dataset--a file by itself on the disk, not saved in a library. As with books, a library can hold your files more neatly and in less space than if you simply throw them around haphazardly.

Purpose

If you store files on TPPAK1, they will be deleted within 2 to 10 days unless you save them on a five-track library called LIB. Your library will remain on TPPAK1 until you scratch it (i.e., delete it) or your account expires. If your account expires, your library will be retained for 30 days before it is deleted. (Backups will be discussed later.)

When you save files outside of a library, they take up a full track, whether they need that much space or not. For example, if you have ten files saved on a disk pack--each using one track--you are using ten tracks of magnetic disk space. If you saved these same files in a five-track library, all ten might fit because they will only occupy the space they need. This space-saving feature of libraries can be important for the following reasons:

1. If you are using a rent pack, you pay for all the space you occupy on that pack. If you take up less space, you save money.


2. If you are using TPPAK1, space is important. Some programs do not run if TPPAK1 runs out of space.


3. Files on TPPAK1 not stored in libraries are deleted within ten days.

If you cannot fit all your files in your library on TPPAK1, talk to your account administrator about rent privileges, and build a library on a rent pack. Delete files you no longer need. Put files you do not use often on a magnetic tape. Tapes are available for rental and purchase at the Computer Center.

Creating a Library with the NEWUSER Command

NEWUSER is a command for setting up a library and a log-on file for you. You must have a library to store files on TPPAK1, and a log-on file will make your work easier. If you are setting up a new account, you can use NEWUSER to build a five-track library on TPPAK1 called LIB.

Read the information the system gives you, and answer the questions. NEWUSER will explain to you what it is doing as you go along. It is designed so that you do not have to know anything about the system. Simply follow the prompts you are given. If you do have questions, ask at the ATLC Information Desk.

If you are a staff member or a graduate student, you may need to have a library on a rent pack instead of on TPPAK1. You must have the RENT SETMAS option on your account; therefore, check with your account administrator before you try to build your library. All WYLBUR account holders are authorized to store files on the temporary disk pack TPPAK1. However, the amount of space available to any one user and the length of time that data can be kept on TPPAK1 is restricted. The following are data storage policies for TPPAK1:

1. Each user may create on TPPAK1 one five-track partitioned library, named LIB. Any file stored in a library is kept until:
• the account is deleted,


• the user deletes that file, or


• the user fails to access the library for 45 consecutive days. If the user does not access the library for 45 consecutive days, the system will archive the entire library to tape cartridge and erase it from DASD. Archived files are kept for one year.
2. The following rules apply for TPPAK1 only. (The **.*** represents the userid.)

WYL.**.***.SCRIPTMP.

WYL.**.***.LIB

Backups and Archives

Users authorized to store files on a rent disk pack may store their files on RENT11 for as long as they maintain their accounts and pay for the disk space. CLEANER checks for a valid userid and RENT privileges; if neither is found, then the file is scratched. CLEANER runs every night after the backups are taken. CLEANER archives the datasets for 90 days, except for the temporary datasets, such as SYS9 and SCRIPTMP. CLEANER uses the rules listed above (Nos. 1 and 2) to determine the status of a dataset.

A disk backup and file archiving facility makes full backups of each disk pack on the IBM system once a week. In addition to full weekly backups, it makes daily "incremental" backups on files that have been changed since the last full or incremental backup. The end result is a daily image of each disk pack, so work done the day before will not be irretrievably lost.

The archiving part moves infrequently accessed disk files from disk to tape. If a file is not used for 45 days, it will be archived to a tape. If you must use an archived file, enter TECH RESTORE. If you have any questions, contact a Technology Support consultant.

You may need to retrieve a file that you inadvertently deleted or wrote over. Any academic user wishing to restore a file should contact a Technology Support consultant at 742-HELP. If it is on a backup tape, it may be restored with a restoration fee paid at the ATLC Receptionist's desk. Any administrative user wishing to restore a file from an archive should contact the TechNet Support Specialist at 742-3869.

Building a Library on a Rent Pack

To build a library on a rent pack, use the WYLBUR EXEC command TECH MAKELIB. One of the prompts will be for the number of tracks you want that library to have. To judge the number of tracks you need, you can check the number of tracks your files are occupying by using the command SHOW DSNAMES (more information).

WYLBUR will respond with a list of your files and how many tracks they occupy. Add the tracks together and take 80% of that number. This is the number to answer when TECH MAKELIB prompts you for the number of tracks you want. This number should be ample space for you to work easily with your files. Enter:

and answer the prompts. You know the number of tracks you want from the calculation done using SHOW DSNAMES. A secondary allocation is not necessary, so you should enter zero at that prompt. The next prompt asks how many directory blocks you need. Estimate the number of files that will be in your library. Each directory block can hold fifteen filenames.

Next, enter the name of the pack that you want to put your library on, such as RENT11. Then choose the format in which you want your library to be. Most users should enter "1" for WYLBUR edit format. This saves space and is the format you should use with most programs and SCRIPT files. Only choose card format if you need 80-column cards (uncompressed, non-WYLBUR) that will be used for batch job input (such as SAS datafiles). These are the only two formats you will normally use.

Using a Library

To save a file as a member of your library, enter:

where lib is the name of your library, "#" means "member," and file2 is the name of the file you are saving. If the name of your library is LIB, you can leave off the library name and simply enter:

You can also enter:

with the same results. To use a file from your library, enter:

where lib is the name of your library, and file3 is the name of the file in your library you want to use. The same rules apply as when you save a file to your library.

To scratch (delete) members of your library, enter:

where lib is the name of your library, and file7 is the name of the file you want to delete. (Refer to Chapter 4: Command Summary for more information on these commands.)

When the Library Gets Full

Another important feature of libraries is condensing. When you replace or delete a file in your library, the space occupied by that file is no longer accessible. Therefore, after you have done a lot of replacing and deleting files, the library becomes full. When you try to save the next file, WYLBUR gives you the prompt:

Answer YES to this prompt, and WYLBUR will prompt for your password and run the job to condense your library. You cannot save into the library until this job has run. Remember to save your file afterward because it was not put into your library. As a safety precaution, save a copy of your file outside of your library until the condense function has been completed.

If you think you are getting close to a mandatory condense from WYLBUR, you can voluntarily condense your library instead of condensing it when you are trying to save a file. You can check the status of your library by using the SHOW DSNAMES command. WYLBUR can tell you how many tracks are being used and the total number of tracks in your library (such as 17 of 23 tracks).

If you have any problems setting up or using your library, you can get assistance at the ATLC Information Desk.

System Messages

As you work on the computer, you will get various messages from the system or WYLBUR giving the status of the machine or a command. Listed below are a few of the most common messages.

Common System Messages

Message	Meaning
n/m: BAD RANGE	The line range you specified, n through m, does not exist.
INVALID COMMAND	You typed in a command WYLBUR could not understand. Type in the command again, correctly.
JOB ENDED	Your job has finished running.
JOB ENDED -- ABENDED	Your job ended abnormally. FETCH your job and enter the command REVIEW 'ABEND' to see the ABEND CODE. Then use WYLBUR HELP facility to find out what it means. For example, the command HELP ABEND S722 gives you an explanation of ABEND S722.
JOB ENDED -- JCL ERROR	Your job did not run because of a Job Control Language (JCL) error. If you are using a command or an EXEC such as NEWUSER, CONDENSE, or TECH SCRIPT, this usually means you typed your keyword (password) incorrectly.
MESSAGE WAITING	The system has a message for you. Press ENTER to view it; press ENTER again to return to the screen.
	There is a hardware problem between your terminal and the computer. You might want to check with the Information Desk. This usually means that the computer has come down or will go down shortly. You can wait or come back later. You have been logged off.
VOID RANGE	The string you were searching for is not in your active file.
	The computer cannot process your command. Press RESET and wait a few seconds. If an "X" and a clock appear (explained in the next message), wait for them to disappear before reentering your command. If the clock is not displayed, press ENTER again. If you see X - f again, the computer may be down. Check with a student assistant at the Information Desk. If the computer is down, you can wait or come back later when it is up and running again.
	This means the computer requires some time to process your last command. When it disappears, you will be able to give your next command.
	You are typing in the wrong part of the screen. Press RESET. Now press the TAB key to move back to a valid part of the screen.
	You tried to type while the computer was in control. Press RESET and wait for the clock to disappear.

If you are getting any other messages and you do not understand what it means, check with the student assistants at the ATLC Information Desk.

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