What command do I type in to check this?
3 Answers
Is this a Linux server? If so, try uname -p
Example:
$ uname -p
x86_64
Note that this only tells you about the Linux kernel, not any particular user-land software (e.g. you can still run 32-bit MySQL on 64-bit Linux). And you could be running 32-bit Linux on a 64-bit CPU.
![](../../users/profiles/1241.webp)
- 913
- 2
- 11
- 16
-
D'oh. I just saw the "linux" tag, so of course it's a Linux server :-). – Matt Solnit Oct 08 '09 at 21:37
You could also check the cpuinfo and look for the "lm" (long mode) flag
less /proc/cpuinfo
output:
flags : ... lm ....
a 32-bit processor won't have this flag.
![](../../users/profiles/21844.webp)
- 312
- 1
- 3
-
1
-
Look at this thread: http://serverfault.com/questions/27590/how-do-i-know-if-i-am-running-32-or-64-bit-linux – jomey Oct 09 '09 at 00:19
In addition to Matt's answer about your kernel, if you're running a Red Hat/CentOS RPM-based distro (which is what most of Rackspace is, typically) you can check the installed userland tools for their bitness with this command:
rpm -qa --queryformat='%{n}-%{v}-%{r}.%{arch}\n' | sort
You're looking for .i386 or .x86_64 on the end. It's entirely possible to have a mix of 32bit and 64bit on a 64bit install based on needs of the server.