NetBackup™ Backup Planning and Performance Tuning Guide

Note on log file creation

When you run multiple tests, you can rename the current log file. Renaming the file causes NetBackup to create a new log file, which prevents you from erroneously reading the wrong set of values.

Deleting the debug log file does not stop NetBackup from generating the debug logs. You must delete the entire directory. For example, to stop bptm from logging, you must delete the bptm subdirectory. NetBackup automatically generates debug logs at the specified verbose setting whenever the directory is detected.

Use care when manipulating the bptm log files if the backup or restore is part of a multiplex (MPX) group that includes unrelated operations. In those instances, the bptm parent process opens the log file once at startup and receives a file descriptor from the operating system. The parent process and child processes write to that file descriptor until all current (and future) jobs that join the MPX group have completed. Unexpected consequences may result if the log file is renamed or deleted while the MPX group is still active.

If the log file is renamed, the file descriptor remains open against the renamed file. And if the next test job joins the same MPX group the new log entries appear in the renamed log file. If the log file is deleted, the file is no longer visible in the directory but the file descriptor remains open. If the next test job joins the same MPX group, the new log entries are written to the open file. Note that the user can no longer access the open file.

This behavior also applies to the MPX groups that have been running for multiple days. If the test job joins an MPX group that became active two days ago, the log entries are in the log from two days ago. If the bptm log directory did not exist two days ago, the bptm processes handling the backup do not generate any log entries.