How To Identify The Passed Kernel Parameter After Rebooting

Kernel by default can accept kernel parameter to extend and modify its kernel parameter modules and kernel options. This can be done initially during the process of boot selection before bootup process. But, what if the server is currently running and you wish to determine the submitted kernel parameters from the last bootup sequence.

Here's a quick post on how to identify the passed kernel parameter of a system from its last bootup event.

Determine Submitted Kernel Parameter of Last Bootup Process

Remember, everything in linux are files. So, simply issue

# cat /proc/cmdline

giving you a similar lines like

ro root=UUID=2ca35552-0bef-43f4-8374-a41c1307d554 rhgb quiet

or

ro root=LABEL=/1 rhgb quiet

The above lines tells us that the kernel bootup received a kernel parameter of ro root=LABEL=/1 rhgb quiet

Kernel Parameter Verification

The default bootup kernel parameters can be verified by simply checking

# cat /etc/grub.conf | grep -v '#' | grep kernel

giving you a similar line like so

kernel /vmlinuz-2.6.25-14.fc9.i686 ro root=UUID=2ca35552-0bef-43f4-8374-a41c1307d554 rhgb quiet

The above is the default grub kernel parameter, which would not reflect any customized kernel parameter submission as show previously.

All is done.