Determining actual DB2® log file usage

The following is the procedure to verify how much space was used by a successful instance of the JnextPlan command:

After JnextPlan has run, log on to the computer where the HCL Workload Automation DB2® server is installed, as the DB2® instance owner (UNIX™) or DB2® Administrator (Windows™).
Open a DB2® command line window or shell, as follows:
UNIX™
Follow these steps:
1. Issue the command su - db2inst1, or change to the subdirectory sqllib of the home directory of the owner of the DB2® instance (by default db2inst1)
2. Launch the command . ./db2profile
Windows™

Select from the Start menu, Programs → IBM DB2 → Command Line Tools → Command Window
Run the following command:
```
db2 "get snapshot for database on TWS" > snapdb.txt
```
where "TWS" must be changed to the actual database name if different
Open the snapdb.txt file and look for a section like this:
```
         Log space available to the database (Bytes)= 244315359
         Log space used by the database (Bytes)     = 484641
         Maximum secondary log space used (Bytes)   = 0
         Maximum total log space used (Bytes)       = 581636
         Secondary logs allocated currently         = 0
```
The value shown in "Maximum total log space used" is the actual space used for the DB2® logs. This space should be allocated to DB2® using primary log files only: therefore, you should change the number of primary log files and their size as necessary to meet this requirement as a minimum.

In addition, you are recommended to allocate a secondary log space to DB2®. A good choice for the secondary log files is half the number allocated for the primary files.

The snapshot command described in step 3 can be run at any time to keep track of the current usage of the DB2® log space, without a noticeable impact on performance. All metrics shown are useful to monitor the current allocation of DB2® primary and secondary logs at any time, and to determine any required changes.