When using some Nagios plugins to check server load and disk space on 64bit systems you may get back
/lib/ld-linux.so.2: bad ELF interpreter: No such file or directory
This means that you dont have the required libraries, To install them on Centos
yum install glibc.i686
The solution above works on CentOS, Fedora, or Red Hat 64bit operating systems; on a Debian or Ubuntu derived system use :
sudo apt-get install ia32-libs