Adjusting database configuration parameters to meet Db2 pureScale environment requirements
After converting your environment for Db2 pureScale, you must make a number of changes to database configuration parameters.
- Ensure that there is sufficient disk space to hold the logs retrieved from members during a log merge. Providing space for two log files per member in the log path, mirror log path, or overflow log path allows one log file to be kept while another log file is being retrieved. Having space for two files helps to avoid the problem of a log merge having to wait for log files to be retrieved.
- To support the additional memory requirements for group restart, rollforward, log merges, and log file retrieval, ensure that the dbheap database configuration parameter is set to AUTOMATIC. You should also use the AUTOMATIC setting if you are making use of table partitioning; this takes into account the memory used to synchronize table partitioning data between the cluster caching facility (CF) and all members.
- To support the additional locking requirements for data coherency between members, ensure that the locklist parameter is set using the XX AUTOMATIC option, where XX is 3% of the total number of pages for all the existing bufferpools.
- If you have large buffer pools, you have not enabled self-tuning memory, and your Db2 server is using nearly all the physical memory on the system, consider decreasing the buffer pool size or enabling self-tuning memory.
- Review the memory considerations for restart light and make any necessary adjustments.