size of log data sets, size, bootstrap data set (BSDS), BSDS (bootstrap data set)" /> Planning your logs

 

Planning your logs

You are recommended to have at least three log data sets, and to use dual logging and log archiving. The following table shows suggested values for log and bootstrap data set definitions that affect the performance of queue manager operation, recovery, and restart. Two sets of values are given; one set is suitable for a test system, the other for a production system or a system that will become a production system.

Table 22. Suggested definitions for log and bootstrap data sets
Definition setting Test system Production system
Log data set size1 10 000 records (40 MB approx.)

Access Method Services rounds to nearest cylinder and allocates 10 080 records.

180 000 records (700 MB or 1 000 cylinders of 3390)
Number of active logs1 3 6
BSDS size 60 records (240 KB approx.) 120 records (480 KB approx.) A primary extent of this size should be sufficient for the maximum number of archive logs that can be recorded in the BSDS (1 000).
Note:

  1. The optimum value for this definition is dependent on the characteristics of the individual system. The values given are intended as a guideline only and might not be appropriate for your system.

Note:
If you are using queue-sharing groups, ensure that you define the bootstrap and log data sets with SHAREOPTIONS(2 3).