This article explains the behavior of the Command Line Interface knob request system reboot on the ACX5448 platform.

In ACX5448, when the request system reboot command is executed, both Junos OS and Linux hosts are rebooted as shown below:

root@acx5448> show system uptime 
Current time: 2019-08-01 18:42:10 NZST
Time Source:  NTP CLOCK 
System booted: 2019-08-01 18:34:53 NZST (00:07:17 ago)
Protocols started: 2019-08-01 18:35:30 NZST (00:06:40 ago)
Last configured: 2019-07-31 23:16:29 NZST (19:25:41 ago) by root
 6:42PM  up 7 mins, 1 users, load averages: 0.28, 0.40, 0.27

root@acx5448>show vmhost uptime 

 Vmhost Current time: 2019-08-01 18:41:32+12:00
 Vmhost Uptime: 
       18:41:32 up 7 min, 0 users, load average: 3.94, 3.26, 1.63
 Vmhost last reboot reason: 0x1:power cycle/failure

The ACX5448 Routing Engine model leverages the NG-RE architecture (See TN303 - Next Generation Routing Engine - Technical Introduction ). As per the NG-RE architecture, the Junos OS runs as a Virtual Machine (VM) on top of a Linux-based host (VM Host). In the NG-RE architecture, if the request system reboot command is executed, only the Junos VM will be rebooted but not the Linux host. The command to restart the VM host in this case would be request vmhost reboot .

However, in the ACX5448 platform, the behavior is slightly different in that both the Junos OS and Linux host are rebooted when the request system reboot command is executed.

This behavior is as per design of the ACX5448 platform and is therefore working as expected.