大一入学的时候因为寝室电压不稳定导致玩PS4的时候显示器时常黑屏，再加上担心哪天忘了交电费玩游戏玩到一半断电导致存档丢失，所以买了个UPS放寝室。
今年因为去医院见习，没什么时间打机，所以就把UPS丢在家里吃灰。直到国庆前几天，从不停电的家竟然停电了。担心断电对系统和硬盘造成损害，所以国庆的时候就把吃灰了几个月的UPS搬了出来，接到Homelab上。

1. 安装与配置

1.1 apt install

我的UPS是APC家的BK650M2-CH，所以用apcupsd进行管理。

sudo apt install apcupsd

插上RJ45网口到USB-A的线

lsusb

查看USB设备连接情况

Bus 001 Device 009: ID 051d:0002 American Power Conversion Uninterruptible Power Supply

1.2 修改/etc/default/apcupsd

因为不是使用 systemd 启动 apcupsd ，所以需要将ISCONFIGURED修改为yes

vim /etc/default/apcupsd

1.3 apcupsd.conf

先备份

cp /etc/apcupsd/apcupsd.conf{,.backup}
vim /etc/apcupsd/apcupsd.conf

修改为

#
UPSTYPE usb
DEVICE 

DEVICE留空，不然会出现STATUS：COMMLOST的错误

查看运行状况

apcaccess 

按需修改关机触发事件

vim /etc/apcupsd/apcupsd.conf

#
# Note: BATTERYLEVEL, MINUTES, and TIMEOUT work in conjunction, so
# the first that occurs will cause the initation of a shutdown.
#

# If during a power failure, the remaining battery percentage
# (as reported by the UPS) is below or equal to BATTERYLEVEL,
# apcupsd will initiate a system shutdown.
BATTERYLEVEL 40

# If during a power failure, the remaining runtime in minutes
# (as calculated internally by the UPS) is below or equal to MINUTES,
# apcupsd, will initiate a system shutdown.
MINUTES 20

# If during a power failure, the UPS has run on batteries for TIMEOUT
# many seconds or longer, apcupsd will initiate a system shutdown.
# A value of 0 disables this timer.
#
#  Note, if you have a Smart UPS, you will most likely want to disable
#    this timer by setting it to zero. That way, you UPS will continue
#    on batteries until either the % charge remaing drops to or below BATTERYLEVEL,
#    or the remaining battery runtime drops to or below MINUTES.  Of course,
#    if you are testing, setting this to 60 causes a quick system shutdown
#    if you pull the power plug.
#  If you have an older dumb UPS, you will want to set this to less than
#    the time you know you can run on batteries.
TIMEOUT 0

一共三个参数，分别是

1.4 开机自启

/etc/init.d/apcupsd enable
/etc/init.d/apcupsd start

2. 测试

拔掉电源
status从变成了ONBATT

Broadcast message from root@homelab (somewhere) (Fri Sep 29 12:10:57 2023):

Power failure on UPS homelab. Running on batteries.

---
触发关机事件
---

Broadcast message from root@homelab (somewhere) (Fri Sep 29 12:52:54 2023):

Remaining battery charge below limit on UPS homelab. Doing shutdown.


Broadcast message from root@homelab (somewhere) (Fri Sep 29 12:52:54 2023):

UPS homelab initiated Shutdown Sequence

Connection to 192.168.1.*** closed by remote host.
Connection to 192.168.1.*** closed.

3. 关机但不关闭供电

测试了几次发现一个严重的问题：
触发关机事件后，主机是正常关机了，但同时UPS关机，不再给其他设备供电。
因为Homelab用的是PN41，内置只有一个nvme和一个2.5寸硬盘位，所以同时外接了一个硬盘柜。UPS断电的时候主机关机，但外接的硬盘还在转，所以断电就能听到一声让人毛骨悚然的“吱~”。
希望主机能够自己关机但不停止UPS对其他设备的供电，所以需要修改默认的关机指令。
先创建一个另外的关机脚本

vim powerfailure_shutdown.sh

# 等待30秒后关机
sleep 30
sudo shutdown -h now

然后修改断电关机指令

cp /etc/apcupsd/apccontrol{,.backup}
vim /etc/apcupsd/apccontrol

将

doshutdown)
    echo "UPS ${2} initiated Shutdown Sequence" | ${WALL}
    #${SHUTDOWN} -h now "apcupsd UPS ${2} initiated shutdown"
    ;;

修改成

doshutdown)
    echo "UPS ${2} initiated Shutdown Sequence" | ${WALL}
    /path/to/powerfailure_shutdown.sh &  # 脚本路径
;;

再次拔掉电源测试，主机关机之后UPS还在持续给硬盘柜断电，让硬盘有足够的停转时间。

参考文章
APCUPSD User Manual
Apcupsd on Debian stretch 9 no connection to UPS?