『可靠性理論』與『機率』打交道，或許恰好在『自然律』之『穩定性』基礎上，頗具功效！所以人們才可以設計『容錯式廉價磁碟陣列』 RAID Redundant Array of Inexpensive Disks ，得到『高』可靠性又『容易』製造的產品！於是由此觀之

Watchdog  do do the “watch” job.

的哩！！

我們要到哪裡找隻『 Watchdog 』呢？如同下面這篇文章所說《 Auto-reboot a hung Raspberry Pi using the on-board watchdog timer 》︰

Luckily for us, the Broadcom BCM2835 SoC on the Raspberry Pi comes with a hardware-based watchdog timer that can do just that. You will find this specially useful if you have a Raspberry Pi in a remote location and the operating system hangs and there’s no one around to reboot it.

在此簡單整理一下︰

# 安裝 watchdog

sudo apt-get install watchdog

# 檢查模組正確性
sudo modprobe bcm2708_wdog

ls -la /dev/wa*
crw------- 1 root root 10, 130  3月 13 11:39 /dev/watchdog

# 驗證後將 bcm2708_wdog 加入 /etc/modules

# 設定開機啟動 watchdog

sudo update-rc.d watchdog defaults

# 修改 watchdog.conf 設定檔︰
sudo nano /etc/watchdog.conf

#
# 指定 watchdog-device	= /dev/watchdog
#
# 取消『#』符號，起始測試
# 
# max-load-1		= 24
# max-load-5		= 18
# max-load-15		= 12
#

 

□︰ 有手冊嗎？

○︰ man watchdog

□︰ 怎麼測試？？

○︰ :(){ :|:& };:

○︰ 自生者自榮！！