Different commands shows different results. If my linux 32 bit or 64 bit?

Question

The system of my VPS is centos 5. I want to know if it is 32bit or 64bit.

> uname -a
Thu May 13 13:49:53 EDT 2010 x86_64 x86_64 x86_64 GNU/Linux

looks like 64 bit.

But

> getconf WORD_BIT
32

Looks like 32 bit.

Which is correct?

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UPDATE

I believe the linux of my VPS is 32 bit. Because I downloaded a 64bit mongodb, found it can't start. And when I downloaded a 32bit instead, it works well.

Answer 1

Well, it depends. It's possible getconf doesn't return the correct value, and it's possible you have a 32-bit kernel on 64-bit hardware. I'd say, however, that the output of uname is what you should go by, as it states that you're running a 64-bit kernel.

Answer 2

uname -a shows whether the OS is 32/64 bit.

Answer 3

The glibc's WORD_BIT seems to be broken, because (in xopen_lim.h) it looks at __INT_MAX__ instead of __WORDSIZE or sizeof(__SWORD_TYPE).

To report the syscall personality of the current process, those commands are equivalent:

uname -m
arch

To change it, assuming your kernel supports it:

linux32
linux64

It is possible to have a 64bit kernel with a 32bit userland. To know what kind of kernel you have:

sudo file /proc/kcore

Your CPU:

cat /proc/cpuinfo