I'm try to upgrade a debian system to 2.6 64 bit kernel with the command

aptitude install linux-image-2.6.32-5-amd64

which works fine.

The system reboots, /vmlinuz -> boot/vmlinuz-2.6.32-5-amd64

all good

however uname -a returns

Linux hostname 2.6.32-5-686 #1 SMP Sun May 6 04:01:19 UTC 2012 i686 GNU/Linux

Am I missing something or is this correct?

3 Answers 3


One does not simply install a 64-bit kernel to change a 32-bit installation to a 64-bit installation. You usually have to completely reinstall the system.

That said, the Debian Wiki has a workaround which can be used to migrate 32 to 64-bit on a live system, but it looks hairy enough that I'd probably just reinstall.

  • I was looking at this, which seemed to suggest that the upgrade of the kernel would lead to uname giving a different result.
    – mark
    Sep 25, 2012 at 19:46

In case anyone else suffers this problem, I just needed to force grub to reconfigure (I had assumed that happened as part of the new kernel install). So

grub-mkconfig -o /boot/grub/grub.cfg

Then the new 64 bit kernel appeared and I could boot from it. After that, a query of uname -a did indeed return x86_64


Had to install the linux-headers too before running

sudo apt-get install linux-headers-3.16.0-4-amd64


grub-mkconfig -o /boot/grub/grub.cfg

and finally reboot the system.

Thanks Mark from the previous answer... Can't up vote right now... don't have enough point :)

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