Sar
On Debian System, sar locates at package sysstat. But sar is not there ready to use even after we executed apt install sysstat.
debian@debian:~$ sar
Cannot open /var/log/sysstat/sa26: No such file or directory
Please check if data collecting is enabled
Solution#
First, go enable the collect system activity infomation toggle
sudo vim /etc/default/sysstat
# Should sadc collect system activity informations? Valid values
# are "true" and "false". Please do not put other values, they
# will be overwritten by debconf!
ENABLED="true"
Then, restart sysstat service
https://www.crybit.com/sysstat-sar-on-ubuntu-debian/