To completely back up your system, you should copy three types of information:
User and system files. User files are usually the largest part of a
system backup. They cannot otherwise be duplicated, except from
hardcopy. Since, in total, they can be the product of several months or
even years of labor, user files can be considered the most important
element within your computer system. All system files are in groups
within the SYS account; most system files are owned by the PUB
group of the SYS account.
The file system directory. The file system directory contains your
account, group, and user structure, plus all associated capabilities. Each
volume set has its own directory that must be saved to provide a complete
backup.
The current system configuration. The system configuration includes
system tables, queues, device I/O attachments, and other parameters.
The various types of data are backed up using different mechanisms:
System configuration information is backed up on a system load tape (SLT).
User and system files, and the file system directory are backed up
on STORE media, which can include tape, DDS, magneto-optical, or disk.
Backing up system configuration files separately from other files is to
your advantage because user, system, and system directory files usually
change often while system configuration files change infrequently.
Also, with the capability of backing up each type of file separately,
you can avoid backing up any inadvertent corruption of system files
while still backing up your other files.
Use the SYSGEN program to create a system load backup to supplement a
STORE backup. The SYSGEN program enables you to back up the system
configuration. You cannot back up operating system and configuration
files with the STORE program. When you use STORE to perform system
backups, you must still use the SYSGEN program to create a system load
tape from which you can reload your system configuration.
To put SLT and store filesets on a single tape, you can use the combined
SLT and Storeset functionality. Refer to Chapter 10, "Backing Up the
System Configuration," for details of using the SYSGEN utility and
combining an SLT and Store set.
