Viswamitra's blog

We have three methods to find the CPU is 32 bit or 64 bit

1) [root@node1 ~]# getconf LONG_BIT
64

or

2) [oracle@node1 dt.d-WIP]$ grep -o -w ‘lm’ /proc/cpuinfo | sort -u
lm

More about CPU modes:

lm flag means Long mode cpu – 64 bit CPU
Real mode  16 bit CPU
Protected Mode  is 32-bit CPU

3) we can also identify using the “uname -a” , but we can install a 32bit linux on 64 bit environment. So first two methods are better than this.

[root@node1 ~]# uname -a

Linux node1.oracle.com 2.6.18-164.el5 #1 SMP Tue Aug 18 15:51:48 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux