syslog_disk_size

Description

syslog_disk_size specifies the maximum disk space for system logs. When the total size of system logs approaches this limit, the oldest log files, including compressed ones, are deleted.

Privilege requirements

• Query the parameter

  The sys tenant and all user tenants can query the value of this parameter by using the SHOW PARAMETERS statement or the GV$OB_PARAMETERS view.

• Modify the parameter

  Only the sys tenant can modify this parameter. User tenants cannot modify this parameter.

Attributes

Considerations

• The system log files stored by this parameter include all compressed and non-compressed log files in the {install_path}/log directory.

• The syslog_disk_size parameter is based on the du -sh (disk usage) principle, which calculates the total disk space occupied by all files in the log directory. This is different from the df -h (disk free) principle, which displays the usage of the entire disk partition, including metadata and cache, and also counts deleted files that are still being used by processes.

• The relationship between the syslog_disk_size parameter and the max_syslog_file_count parameter:

  1. max_syslog_file_count=0 and syslog_disk_size=0: No log recycling is performed until the disk is full.
  2. max_syslog_file_count=0 and syslog_disk_size>0: When the total size of logs approaches syslog_disk_size, the oldest log files are deleted to recycle space.
  3. max_syslog_file_count>0 and syslog_disk_size=0: When the number of log files of a certain type exceeds max_syslog_file_count, the oldest log files are deleted to recycle space.
  4. max_syslog_file_count>0 and syslog_disk_size>0: When the number of log files of a certain type exceeds max_syslog_file_count or when the total size of logs approaches syslog_disk_size, the oldest compressed log files are deleted to recycle space.

Examples

Set the maximum disk space for system logs to 50 GB.

obclient> ALTER SYSTEM SET syslog_disk_size='50GB';

References

• Logs
• Log control methods