From blog.taragana.com
How to install sar, sadf, mpstat, iostat, pidstat and sa tools on CentOS / Fedora / RHEL
The following command can be used to install sar, sadf, mpstat, iostat, pidstat and sa tools on RPM based systems like CentOS, Fedora, RHEL (Red Hat Enterprise Linux):
As root type the followiung command (on console / terminal):
yum -y install sysstat
When you are not root but have sudo configured for your account then use:
sudo yum -y install sysstat
This installs the sysstat tools which contains the above mentioned utilities.
iostat is an essential utility to fnd out about IO load on your system and ways to combat it.