Raspberry Cluster Rack 19"

Raspberry Rack 19" (Cluster/Server)

1x Steel Tray 19" 1U (or equivalent)
1x Raspberry Pi 3 with LCD16x02 I2C for Node o DNS Server
2x Raspberry Pi 3 for LAMP (Apache2, PHP, MySQL)
1x MeanWell 5v-5A (25w) Power Supply
3x Reboot Buttons

Optional: external ACT LED (SD CARD)
Only Raspberry B+

Insert this code in config.txt

dtoverlay=w1-gpio
dtparam=act_led_gpio=26 (number XX - your choice)

and many beautiful things...