Check Linux performance with sar

sar -q  run queue and load average
sar -r  memory free and used
sar -n ALL  network statistics
sar -u CPU
sar -b  overall I/O
sar -d  individual block device I/O
sar -w context switches
sar -S -f /var/log/sa/sa07   swap space historical
sar -s  start time