Disk

/etc/sysctl.conf

vm.dirty_writeback_centisecs = 1500
vm.dirty_expire_centisecs = 9000
vm.dirty_background_ratio = 20
vm.dirty_ratio = 80
vm.swappiness = 5

Who is waking up the disks?

echo 1 > /proc/sys/vm/block_dump

and monitor with dmesg

CPU

/sys

echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo powersave > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor

Network

100 Mbps

ethtool -s eth0 advertise 0x008; # 0x020 for 1 Gbps