How do I see why a server reboot is needed after a cPanel update?

Question

How do I see why a server reboot is needed after a cPanel update?

Answer

After a cPanel update, you may see a warning in WHM that reports you need to reboot the server to apply it. You can confirm what changes require a reboot by following these steps.

1. Log in to SSH or use the WHM Terminal as root.

2. Run the following command:

   # whmapi1 system_needs_reboot

In the example below, we can see that a reboot is needed due to systemd, openssl-libs, and kernel updates.

# [root@server ~]# whmapi1 system_needs_reboot
---
data:
 details:
   kernel:
     boot_version: 3.10.0-1160.144.1.el7.tuxcare.els5.x86_64
     running_version: 3.10.0-1160.144.1.el7.tuxcare.els3.x86_64
   updates:
     openssl-libs: 1:1.0.2k-26.el7_9.tuxcare.els9
     systemd: 1:219-78.el7_9.9.tuxcare.els3
 needs_reboot: 1
metadata:
 command: system_needs_reboot
 reason: OK
 result: 1
 version: 1