Note: This is an RHCE 7 exam objective.
Install the sysstat package if it’s not already the case:
# yum install -y sysstat
Activate the sysstat service at boot (if it’s not already the case):
# systemctl enable sysstat
Produce a report for a given day (here the 11th) (-u for CPU usage, -r for memory usage, -dp for disk activity, -n DEV for network activity):
# sadf -d /var/log/sa/sa11 -- -u -r -dp -n DEV
Performance analysis starts with the top command that displays the current activity (CPU, memory) on a server. glances, available through the EPEL repository, is a less known command that displays even more information than top (network usage, disk I/O, filesystem usage).