Monitoring the Logical Log for Fullness

You can use the following command-line utilities to monitor logical-log files.

onstat -l

The onstat -l command displays information about physical and logical logs.

The output section that contains information on each logical-log file includes the following information:

• The address of the logical-log file descriptor
• The log file number
• Status flags that indicate the status of each log (free, backed up, current, and so on)
• The unique ID of the log file
• The beginning page of the file
• The size of the file in pages, the number of pages used, and the percentage of pages used

The log file numbers in the numbers field can get out of sequence if you drop several logs in the middle of the list or if the database server dynamically adds log files.

For more information on and an example of onstat -l output, see the IBM Informix Administrator's Reference.

oncheck -pr

The database server stores logical-log file information in the reserved pages dedicated to checkpoint information. Because the database server updates this information only during a checkpoint, it is not as recent as the information that the onstat -l option displays. For more details on using these options to display reserved page information, see the IBM Informix Dynamic Server Administrator's Reference.

You can view the checkpoint reserved pages with the oncheck -pr command. Figure 61 shows sample output for one of the logical-log files.

...
Log file number             1
Unique identifier           7
Log contains last checkpoint Page 0, byte 272
Log file flags              0x3  Log file in use
                                 Current log file
Physical location           0x1004ef
Log size                    750 (p)
Number pages used           1
Date/Time file filled       01/29/2001 14:48:32
...