Resizing persistent data store files

After you have used historical data collection for a while, you might determine that the amount of space allocated initially is not sufficient. In this case, you can change the size of the file allocation.

About this task

Important: The content in this section was created for and applies to the original persistent data store, referred to as PDS V1. A new PDS version (referred to as PDS V2) now exists. PDS V1 will eventually be deprecated.

There are two ways to increase the amount of space allocated to historical data collection files:

Change the total amount of space allocated for the persistent data store libraries and overhead information
Add additional files to the data set

You change the amount of space allocated to the persistent data store by editing the Kpp_PD_CYL parameter in the RTE configuration profile. However, editing the parameter does not necessarily mean that the files are automatically resized based upon the new allocation.

There are two processes that re-initialize the persistent data stores. One process runs inside the address space and does not redefine the files, so their size does not change. The other process is a batch process that deletes and redefines the files. The following parameter flags in the RTE configuration profile force the batch process:

RTE_PDS_BATCHINT_FLAG: The default is N. If this flag is set to Y, the batch process is run and the files are deleted and redefined.
RTE_PDS_BACKUP_FLAG: The default is N. If this flag is set to Y, the batch process is run so a backup of the data in the persistent data store can be made.
RTE_PDS_EXPORT_FLAG: The default is N. If this flag is set to Y, the batch process is run so an archive of the data in the persistent data store can be made.

If all these flags are set to N, you have to delete the data sets and recreate them by using Submit batch jobs to complete the PARMGEN reconfiguration process.

Another way to add more space is to increase the value of the product-specific parameter Kpp_PDS_FILE_COUNT. To determine the allocation size for each file, the configuration software divides the total Kpp_PD_CYL allocation by the file count. If you decide to use this method, then after you run the Submit job and everything completes successfully you add one or more files by issuing a modify command against the address space:

/F stc_name,KPDCMD ADDFILE GROUP=groupid FILE=DSN:dsname

Where:

groupid: Specifies the unique group ID of the file group to which a file is to be added.
dsname: Specifies the fully-qualified name (no quotation marks) of the physical data set that is to be added to the group specified by groupid.