What is the significance of ILOG FILE 1 SUBFILE 0 DSN hlq.LOG01#0 pages 200 for Sysview for Db2

Products

• SYSVIEW Performance Management Option for DB2 for z/OS

Issue/Introduction

What is the significance of the Sysview Performance Management Option for Db2 for z/OS (IDB2) 
ILOG FILE 1 SUBFILE 0 DSN hlq.LOG01#0 PAGES 200?

Can the 200 value be increased? If so will it hold more data?

Resolution

DSN hlq.LOG01#0 PAGES 200 describes the dataset where GSS is going to write the Db2 messages.

There should be a set of files for each Db2 ssid where pages in the number of 4K pages to be allocated to the subfile.
This value must be 5 or greater.

Default: 5

The space requirement for these files is based on the number of ILOG PAGES that has been specified for them to hold.
If all the ILOG PAGES can be allocated within the Primary space allocation then there will be no expansion into the secondary extents.
Listcat will not show how many ILOG Pages are available in the Virtual file and this is what controls the ILOG full message not how
much space is used in the physical VSAM file. If you get an ILOG full message then all the ILOG Pages have been used.