uname -r returns the wrong kernel version

Question

I upgraded from Ubuntu 12 to 14.04 and ran a check at the end of the process to verify everything went right. here is the output of uname -a

Linux odoo 2.6.32-042stab092.3 #1 SMP Sun Jul 20 13:27:24 MSK 2014 x86_64 x86_64 x86_64 GNU/Linux

and then the output of lsb_release -a

No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 14.04.1 LTS
Release:    14.04
Codename:   trusty

So it seems that the system was updated but the kernel was not.

Seeing this, I manually downloaded and installed the 3.16 kernel with these steps:

cd /tmp/

wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.16-utopic/linux-headers-3.16.0-031600-generic_3.16.0-031600.201408031935_amd64.deb
wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.16-utopic/linux-headers-3.16.0-031600_3.16.0-031600.201408031935_all.deb
wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.16-utopic/linux-image-3.16.0-031600-generic_3.16.0-031600.201408031935_amd64.deb

sudo dpkg -i linux-headers-3.16.0-*.deb linux-image-3.16.0-*.deb

but after the reboot, uname -mrs still tells me

Linux 2.6.32-042stab092.3 x86_64

How can I check if the uname command is lying or if the kernel has really not been updated?

Solution

Not exacly.

uname will tell you what kernel is running, not which is installed. So you might have installed the new kernel, but the system would only be running it after a reboot.

After you have installed a new kernel, especially manually, you will need to run sudo update-grub in a terminal window and reboot afterwards.

If the kernel 3.16 was installed correctly, be sure that it is chosen in GRUB2, when booting your PC. To be sure, you can select the "Advanced option for Ubuntu" option in grub. There all your installed kernels are present.

But the sudo update-grub part is crucial when manually installing kernels.