io_status not in CentOS 5?

So, I'm currently working on a project to monitor my linode's usage where ever I'm at but I ran into a small hickup.

[root@somken proc]# cat /proc/io_status

cat: /proc/io_status: No such file or directory

I'm not sure what to do. Any ideas?

I'm running current x86 version of CentOS 5.2.