overflowlogpath - Overflow log path configuration parameter
The overflowlogpath parameter specifies a location for Db2® databases to find log files needed for a rollforward operation, as well as where to store active log files retrieved from the archive. It also gives a location for finding and storing log files needed for using db2ReadLog API.
- Configuration type
- Database
- Parameter type
- Configurable online
- Propagation class
- Immediate
- Default [range]
- NULL [any valid path ]
This parameter can be used for several functions, depending on your logging requirements.
- Use the overflowlogpath parameter to specify a location for Db2 databases to find log files that are needed for a rollforward operation. It is similar to the OVERFLOW LOG PATH option on the ROLLFORWARD command. Instead of always specifying OVERFLOW LOG PATH on every ROLLFORWARD command, you can set this configuration parameter once. However, if both are used, the OVERFLOW LOG PATH option overwrites the overflowlogpath configuration parameter, for that particular rollforward operation.
- The benefit comes from reducing the I/O cost on the active log path and allowing more log files to be stored in the active log path.
- If logsecond is set to -1, you can specify a directory for Db2 to store active log files retrieved from the archive with the overflowlogpath parameter. Active log files have to be retrieved for rollback operations if they are no longer in the active log path. Without the overflowlogpath parameter set, Db2 databases retrieve the log files into the active log path. Use the overflowlogpath parameter to provide additional resource for Db2 databases to store the retrieved log files.
- When Advanced Log Space Management (ALSM) is enabled, if the extraction files have I/O errors, an attempt to retrieve the associated log from the archive will be made. For this reason, it is recommended you set an overflowpath parameter to provide additional resource for Db2 databases to store the retrieved log files.
- If you need to use the db2ReadLog API for replication, for example, use the overflowlogpath to specify a location for Db2 databases to search for log files that are needed for this API. If the log file is not found (in either the active log path or the overflow log path) and the database is configured to archive logs by using the logarchmeth1 or logarchmeth2 parameters, Db2 retrieves the log file. Also use the overflowlogpath parameter to specify a directory for Db2 databases to store the log files retrieved.
- You can specify a location for Db2 databases to retrieve log files that are required for a BACKUP DATABASE INCLUDE LOGS operation.
To set overflowlogpath, specify a string of up to 242 bytes. The string must point to a path name, and it must be a fully qualified path name, not a relative path name. The path name must be a disk directory. You cannot specify overflowlogpath as an empty string.
Note: The database partition number and a log stream ID are automatically appended
to the path, for example, /home/dbuser/dblogs/NODE0000/LOGSTREAM0000/. If you
are creating logs in a multiple partition database environment, such as Db2
pureScale® or a partitioned
database environment, you must copy log files into the log directories, otherwise your logs might be
incomplete.