Increase the size of the History files HSTACCTG and HSTSTATS

Products

• SYSVIEW Performance Management Option for DB2 for z/OS

Issue/Introduction

To increase the size of the Sysview for Db2 History files HSTACCTG and HSTSTATS data sets the following steps have to be run:

1) Allocate the new History files with the new size.

The online history VSAM files are allocated during the post install process. A sample JCL member for allocating the VSAM files is created in db2ssid
VSAM in the SOURCE library. 

See

History Datasets

 

 Use the IDB2UIFI utility to unload the data from the old History files.
. Shutdown the SYSVIEW for Db2 Data Collector started task.
. Load the data into the new History files.
. Start again the SYSVIEW for Db2 Data Collector started task with the new History files.
  
What happens to the IFCID records created between the unload and the shutdown of the SYSVIEW for DB2 Data Collector?. 
 
During this time Db2 address spaces will create IFCID records that will be still written to the current History files HSTSTATS and HSTACCTG data sets.

Environment

Release : 20.0

Component : SYSVIEW Performance Management Option for DB2 for z/OS

Resolution

It is difficult to avoid losing IFCID records when the History files are increased.
  
When you run the IDB2UIFI UNLDHIST (Unload) Job there will be more IFCID records stored in the History files after the last IFCID record is unloaded and the stop of the SYSVIEW for Db2 Data Collector started task. 
  
The only way we could envision increasing the History files without losing any data would be to start a second SYSVIEW for Db2 Data Collector started task with the new History increased files while the old SYSVIEW for Db2 Data Collector started task continues to run.
  
After History files have been loaded to the second SYSVIEW for Db2 Data Collector started task you can stop the old SYSVIEW for Db2 Data Collector started task and you will have all the IFCID records in the new History files in the new SYSVIEW for Db2 Data Collector started task.