This chapter describes the processes for handling the backup
media. The subjects include:
Preparing the Backup Device
Checking the Console
Replying to a Media Request
Pending Media Requests
Denying a Media Request
Using REPLY and RECALL
Automatically Assigning Devices
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.