"reboot" or "shutdown -r now": what restart command is safer?

We have in our organization around ~500 RedHat Linux machines.

On all the machines we installed applications and services under /etc/init.d, and oracle RAC servers. We intend to perform yum updates on all machines and after that take a reboot.

So I was wondering what command is safer:

reboot

or

shutdown -r now

Solution 1:

For Red Hat systems, there is no functional difference between reboot and shutdown -r now.

Do whatever is easier for you.

Solution 2:

Shutdown is preferable because it allows you to specify the reason for the drastic action -- something you should always do. The message will be recorded in the log(s) for posterity. For example:

shutdown -r now 'Kernel upgrade requires reboot'

You can also perform a scheduled reboot -- by specifying something other than now as the reboot time:

shutdown -r 22:00 'Work around kernel memory leak'

Then your users will get periodic reminders to get out and so on -- the process will be more orderly and professional.

Solution 3:

Using reboot is safer.

Using reboot your intent is clear and there is no way to mistype it for something else like shutdown -t now which could leads to a few headache if you are using on a remote server with limited control.