Possible to upgrade kernel to 64-bit?

InverseOfNeo

Diamond Member
Nov 17, 2000
3,719
0
0
I am currently running CentOS 5 32-bit. Is there a way I can install/upgrade the kernel only to 64-bit?

Thank you.
 

PreferLinux

Senior member
Dec 29, 2010
420
0
0
I suspect so, but I don't actually know. I know you can use a 64-bit kernel with 32-bit software and libraries.
 

InverseOfNeo

Diamond Member
Nov 17, 2000
3,719
0
0
Yea, I know that 32-bit software and libs can run on 64-bit kernel. I have a 32-bit system running and I want to upgrade it to 64-bit, but only very few packages that I will then upgrade manually. I suspect there I cant, or at least Google points me to the sign that says I cant.
 

Nothinman

Elite Member
Sep 14, 2001
30,672
0
0
In Debian you just install the correct kernel because they offer amd64 kernels in the 32-bit repositories, but I don't know if CentOS has similar packages available.
 

InverseOfNeo

Diamond Member
Nov 17, 2000
3,719
0
0
I tried installing the 64-bit kernel. It said that it's cannot be installed on a 32-bit system. I would have then selected the correct kernel at boot up. This would work if I were switching to a different 32-bit kernel.
 

Nothinman

Elite Member
Sep 14, 2001
30,672
0
0
If the CentOS packages don't work like that then your only real option is to compile one yourself.
 

Scarpozzi

Lifer
Jun 13, 2000
26,392
1,780
126
I think there's a huge difference between can you and should you... You probably could get it to work, but you'll probably see a ton of errors. I've been doing systems administration long enough to know that it's worth avoiding the headaches and doing clean installs where possible. It would be far easier though to tar up the directories for the apps you need, snag your configs from /etc, and reinstall Cent OS 5-64. There are some major differences in the libraries and applications that Red Hat and Cent OS supports that require a lot of care and feeding even under normal circumstances. If you tackle this, you'd better have a Cent box somewhere already running 64 bit so you can copy libraries and get all your directory rights set correct so new 64-bit applications will have what they need to function.
 

Nothinman

Elite Member
Sep 14, 2001
30,672
0
0
I think there's a huge difference between can you and should you... You probably could get it to work, but you'll probably see a ton of errors. I've been doing systems administration long enough to know that it's worth avoiding the headaches and doing clean installs where possible. It would be far easier though to tar up the directories for the apps you need, snag your configs from /etc, and reinstall Cent OS 5-64. There are some major differences in the libraries and applications that Red Hat and Cent OS supports that require a lot of care and feeding even under normal circumstances. If you tackle this, you'd better have a Cent box somewhere already running 64 bit so you can copy libraries and get all your directory rights set correct so new 64-bit applications will have what they need to function.

If that's the case then RHEL and CentOS are both severely broken. The Linux kernel run 32-bit binaries just as well as 64-bit ones, so if the 32-bit kernel works then the 32-bit one should work exactly the same. Apps that interact directly with the kernel may have issues if poorly written, but most like iptables should've been fixed a long time ago. I've been running a Debian 32-bit install with a 64-bit kernel for probably close to 2 years now without issue.
 

Scarpozzi

Lifer
Jun 13, 2000
26,392
1,780
126
If that's the case then RHEL and CentOS are both severely broken. The Linux kernel run 32-bit binaries just as well as 64-bit ones, so if the 32-bit kernel works then the 32-bit one should work exactly the same. Apps that interact directly with the kernel may have issues if poorly written, but most like iptables should've been fixed a long time ago. I've been running a Debian 32-bit install with a 64-bit kernel for probably close to 2 years now without issue.

You're right. I've seen more problems out of VMware Tools (kernel patch makes NIC disappear) & low level stuff like EMC PowerPath ceasing to function and luns disappearing due to unsupported kernel upgrades...and that wasn't even talking about switching 32-64 bit....

As I said, you can make it work, but after installing the kernel, you'll get to run through all the fun systems disk/network/yum config....and you never know what errors you'll hit. Either way, take my advice and tar up all your stuff before you start...especially any database stuff. It'll make it easier to do a clean install later.

I can typically get CentOS 64 installed in less than 30 minutes or clone a VM in less than 10. :)