3-28 IBM Informix OnLine Database Server Administrator’s Guide

Add a Logical Log File

Ingeneral, log files become free after the file has been backed up to tape and
alllogical log records within the file are associated with closed transactions.
(Referto page 3-39.) It is possible for one logical log file to become free earlier
than another logical log file with a lower ID number. For example, nothing
preventslogical log number 10 from becoming free (status F) while the status
of logical log number 8 remains unreleased (statusU).
However,OnLine cannot skip a logical log file that is unreleased to make use
of the space available in the free logical log file. That is, although the logical
logfiles do not necessarily become free in sequence, OnLine is required to fill
thelogical log files in sequence. If OnLine fills the current logical log file and
the next logical log file in sequence is unreleased (statusU), OnLine
processingis suspended until the log file is freed. It makes no difference that
other logical log files are free.
Add a Logical Log File
Add a log file to increase the total amount of disk space allocated to the
OnLine logical log.
You cannot add a log during an archive (quiescent or online).
The newly added log or logs do not become available until you create a
level-0 archive.
Verifythat you will not exceed the maximum number of logical logs allowed
in your configuration, specified asLOGSMAX.
Ifyou are logged in as user informix, you can make this change from within
DB-Monitoror from the command line. If you are logged in as root, you must
use the command-line option.
OnLine must be in quiescent mode. You add log files one at a time.
4 4 10 16 22
5 5 11 17 23
6 6 12 18 24
Logical
log file 1st rotation
ID number 2nd rotation
ID number 3rd rotation
ID number 4th rotation
ID number
(2 of 2)