Issue

• crashkernel パラメーターを設定すると kdump サービスが起動できません。

$ systemctl start kdump
Job for kdump.service failed.See 'systemctl status kdump.service' and 'journalctl -xn' for details.
$ systemctl status kdump.service
kdump.service - Crash recovery kernel arming
   Loaded: loaded (/usr/lib/systemd/system/kdump.service; enabled)
   Active: failed (Result: exit-code) since Wed 2014-06-11 10:34:48 CEST; 3min 10s ago
  Process:2259 ExecStart=/usr/bin/kdumpctl start (code=exited, status=1/FAILURE)
 Main PID:2259 (code=exited, status=1/FAILURE)

Jun 11 10:34:47 rhel7a systemd[1]:Starting Crash recovery kernel arming...
Jun 11 10:34:48 rhel7a kdumpctl[2259]:No memory reserved for crash kernel.
Jun 11 10:34:48 rhel7a kdumpctl[2259]:Starting kdump:[FAILED]
Jun 11 10:34:48 rhel7a systemd[1]: kdump.service: main process exited, code=exited, status=1/FAILURE
Jun 11 10:34:48 rhel7a systemd[1]:Failed to start Crash recovery kernel arming.
Jun 11 10:34:48 rhel7a systemd[1]:Unit kdump.service entered failed state.

• kdump を動作させる正しい crashkernel パラメーターは何ですか?
• カーネルのパニック時に "crashkernel reservation failed - memory is in use" エラーが発生します。