Filter
Top Products
4-50 IBM Informix OnLine Database Server Administrator’s Guide
Verify Current Configuration
Verify Current Configuration
As its first task, tbtape reads the root dbspace reserved pages from the first
block of the tape. These pages contain both the configuration file values at the
time of the level-0 archive and a complete listing of all dbspaces and chunks
that were defined at the time. The tbtape process verifies that the current
configuration is compatible with the configuration information contained on
the tape. As part of the verification, tbtape displays the list of chunks to the
screen. Press F3 or CTRL-B to continue.
The following message appears:
Verifying physical disk space, please wait.
If the two configurations are not compatible (for example, if the value of
USERS on the tape is 45 and the value of USERS in the current configuration is
30), the restore fails and error messages are returned to the user.
Prompt for Logical Log Backup
If tbtape confirms the configuration, it also determines if any logical log files
are available on disk. If so, tbtape prompts you if you want to back up these
logical log files.
You must back up the logical log files to tape to roll them forward after the
archive portion of the restore is complete. If you do not back up the files now,
the restore procedure overwrites the log file pages and the data is lost.
Enter a Y to indicate that you want to back up any logical log files and mount
a tape on the logical log backup tape device, LTAPEDEV. Verify that the tape
drive is online and press RETURN. If necessary, tbtape prompts for additional
tapes.
The tbtape process backs up each logical log file on disk, whether the log file
status is unreleased or backed up (U or U-B). Consequently, this backup
might provide you with an additional copy of a specific logical log file.
This redundancy is harmless and serves as a form of insurance. In any
rollforward, you must have all tapes available, in sequence. Thus, an extra
copy of the tapes gains you a fall-back in case of failure or loss and costs you
only the time of the backup.