Dump data set size storage requirements
When planning for your Db2 subsystem storage, you must reserve enough space for the dump data sets. The storage requirements depend on factors such as the number of dump data sets you have defined and whether you invoke authorized Language Environment® functions.
- Have at least two dump data sets.
- Have approximately
1000 cylinders for all dump data sets.
If you invoke authorized Language Environment functions, a different style of dump might be generated, which requires approximately 520 cylinders.
- Have 3.25 MB of space for Db2 volatile summary storage data.
Summary data in dumps is usually enough to diagnose most problems. In addition to summary data, Db2 also requests a SDUMP from the operating system to provide these additional storage areas if enough space is available in the dump data set:
- Db2 system services address space
- Db2 database services address space
- Db2 distributed data facility (DDF) address space
- Allied address space of the failing allied task
- IRLM address space for data sharing environments
Db2 passes the following parameters to the SDUMP service aid through the SDATA keyword: SQA, ALLPSA, LSQA, SUMDUMP, and CSA (subpools 231 and 241).
After Db2 SVC dump processing is complete, z/OS® issues message IEA911E to indicate whether enough space was available in the dump data set to contain the requested storage areas. If this message indicates that a partial dump was taken, but the 3.25 MB of summary storage is available in the dump, this dump is probably enough for problem diagnosis. Otherwise, IBM® Software Support might request that you re-create the problem if storage areas that are required for problem determination are not included in the dump.