IBM 000-8697 Manual Do Utilizador

Operating OnLine

For further information about the relationship of the current configuration to
the values in the configuration file ($

), refer

to

.

In the event of a system failure, OnLine can restore all data that has been
archived. Without archives, you cannot perform a restore.

Do not use the OnLine data-migration utilities to unload data as a substitute
for a complete archive. None of the data-migration utilities are coordinated
with the information stored in the logical log files. You cannot roll forward
information from the logical log without the archives.

To ensure the integrity of your archives, periodically verify that all OnLine
data and control information is consistent before you create a level-0 archive.
Refer to

 for a detailed explanation of this consistency check.

The

TAPEDEV

configuration parameter specifies the archive tape device. The

value you choose for

TAPEDEV

 has the following implications:

■

If the archive device differs from the logical log backup device, you
can schedule online archives without regard to the amount of free
space remaining in the logical log.

■

You can create remote archives if you specify

TAPEDEV

 to be a tape

device managed by another host machine.

■

If you specify /dev/null as the archive device, you avoid the
overhead of the archive. However, you cannot perform a restore.

Look at the copy of your configuration file and compare the values specified
by

TAPEDEV

 and

LTAPEDEV

.

LTAPEDEV

 is the logical log tape device.

Ideally,

TAPEDEV

and

LTAPEDEV

each specify a different device. When this is

the case, you can execute online archives whenever you choose. The amount
of free space in the logical log is irrelevant.