Output of the "/var/log/messeges" after OS panic

Issue

• When the system is rebooted after a panic, the logs already outputted to "/var/log/messages" are outputted again. Is it a specification?

• The issue occurs under the following conditions.

  • "Storage" option in the "/etc/systemd/journald.conf" is commented out

  • "/var/log/journal" has been created to save journal logs.

  • /var/log/messages

  Dec  2 00:59:06 RHEL7 root: testtest  *1
  Dec  2 01:03:50 RHEL7 rsyslogd: [origin software="rsyslogd" swVersion="7.4.7" x-pid="443" x-info="http://www.rsyslog.com"] start
  Dec  2 01:03:50 RHEL7 rsyslogd-2307: warning: ~ action is deprecated, consider using the 'stop' statement instead [try http://www.rsyslog.com/e/2307 ]
  Dec  2 00:52:42 RHEL7 journal: Runtime journal is using 6.2M (max 49.7M, leaving 74.5M of free 490.8M, current limit 49.7M).
  Dec  2 00:52:42 RHEL7 kernel: Initializing cgroup subsys cpuset
  <snip>
  Dec  2 00:59:06 RHEL7 root: testtest  *2
  Dec  2 01:03:44 RHEL7 journal: Runtime journal is using 6.2M (max 49.7M, leaving 74.5M of free 490.8M, current limit 49.7M).
  Dec  2 01:03:44 RHEL7 journal: Runtime journal is using 6.2M (max 49.7M, leaving 74.5M of free 490.8M, current limit 49.7M).
  Dec  2 01:03:44 RHEL7 kernel: Initializing cgroup subsys cpuset
  
  *1 Executing "logger testtest" before a panic.
   Dec 2 01:00 : "echo c > /proc/sysrq-trigger" to generate a panic.
  *2 The log is outputted again.