Customizing NGT products
Checkpoint data set considerations
For each subsystem, the installation process creates an NGTCKPT data set named UserHLQ.SSID.CKPT001.
Do not place this data set under control of any compression or DASD management software package, as interference causes processing problems.
Consider the following points:
You cannot copy a checkpoint data set, although you can dump it and restore it. Attempts to copy the checkpoint data set result in a user abend code of U0008.
If the NGTCKPT data set UserHLQ.SSID.CKPT001 fills up, NGT automatically allocates a HLQ.CKPT002 data set to prevent failures. It is important to keep this CKPT0001 low level qualifier when you create your checkpoint data set in the $725ALOC installation job.
The $725ALOC allocates the Checkpoint dataset with these values. SPACE='CYL,(10,50)',RECORG=LS
On a highly dynamic subsystem where thousands of NGT utility job execute daily, you may want to consider increasing the size to SPACE=’CYL,(10,100)’
BMC recommends that you avoid redefining the checkpoint data set. Redefining the checkpoint data set causes loss of common data that BMC Next Generation Technology (NGT) products use. If you need to redefine the checkpoint data set, either stop all NGT product jobs or schedule the redefinition when no NGT product jobs are active.
Call BMC Customer Support before you redefine the checkpoint data set.
BMC recommends that you reorganize the checkpoint periodically. For more information, see .
Place the checkpoint data on a DASD volume that is backed up daily.
Run the NGTDISP command regularly, and run QUICKEXIT for the specified UID to clean up any failed jobs that have RESTARTABLE or MUST COMPLETE status. Adjust the value of the +OUTPUTAGE parameter to reduce the time that completed jobs remain in the checkpoint data set. For more information, see .
Block size considerations
The minimum block size is 4096. Generally, the larger the block size the better the performance of loading NGT products before execution. Since this occurs only once per utility step, the block size is a not a major consideration unless you use a small block size such as 6144.
In this case, for certain utility functions against small DB2 spaces (for example, copying a table space of less than 10 cylinders) a disproportionate number of Execute Channel Programs (EXCPs) reported is attributable to program fetch activity.
Starting NGT Subsystem
Use the following procedure to start NGT Subsystem.
Issue the following operator command:
When NGT Subsystem is fully initialized, it issues message NGTC199 to the console.
BMC recommends that you place this start command in member COMMNDXX of SYS1.PARMLIB so that NGT Subsystem automatically starts during the IPL process.
If you are using data sharing, you must start the CBDSS on all LPARs where any member of the DB2 group might be started.