As iostat is part of the sysstat package, we should ensure that the statistics-gathering elements are enabled. Debian, Mint, and Ubuntu users should modify the /etc/default/sysstat file and make sure that the ENABLED variable resembles this line:
ENABLED="true"
Red Hat, Fedora, CentOS, and Scientific Linux users should make sure that the SADC_OPTIONS variable in /etc/sysconfig/sysstat is set to the following:
SADC_OPTIONS="-d"
Once these changes are complete, restart the sysstat service with this command as a root-level user:
sudo service sysstat restart
