Chapter 8 Handling Media Requests

This chapter describes the processes for handling the backup media. The subjects include:

	NOTE: Instructions for using backup devices in this chapter are general procedures that apply to most devices. Your devices may operate differently. Refer to the documentation for each device for exact instructions and additional information.

Unless your backup devices are configured to be automatically allocated, when a user (or a user's program) needs to use a backup device, you see a media request at the console. For example:

   ?16:04/#S37/23/LDEV# FOR "T" ON MEDIA (NUM)?

The media request asks you to assign an LDEV number to the file named in the request. This process is called allocating the device. The request above asks you to assign a logical device to the file T.

It tells you the time it arrived (16:04 in the example above), the job or session that sent it (#S37 in the example above), and the process identification number (called the PIN) of the program or command that sent the request (23 in the example).

Depending upon your system configuration, the system may or may not answer media requests automatically. Refer to "Automatically Assigning Devices" later in this chapter. If it does, you need only to prepare the backup device for use. If the system does not answer media requests automatically, you must prepare the backup device and reply as explained in "Replying to a Media Request," below.