雜七雜八寫一下

 解決卸載失敗問題 “device is busy”

umount: /dev/sda1: device is busy

$ fuser -vm /dev/sda1
/dev/sda1 6015c 6132

亦使用命令「ps auxw | grep PID」獲知個別程式的詳細資訊：

$ ps auxw | grep 6132
johndoe 6132 0.4 3.0 220017 57104 ? S+ 18:27 0:00 rhythmbo

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使用 netselect-apt 選擇最佳鏡像站台加入 sources.list

      # ls sources.list
      ls: sources.list: File or directory not found
      # netselect-apt stable
      (...)
      # ls -l sources.list
      sources.list

直接用這個也可以

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# Debian packages for stable

deb http://debian.cs.nctu.edu.tw/debian/ stable main contrib

# Uncomment the deb-src line if you want 'apt-get source'

# to work with most packages.

deb http://debian.cs.nctu.edu.tw/debian/ bullseye main contrib non-free

# Security updates for stable

#deb http://security.debian.org/ stable/updates main contrib

deb http://deb.debian.org/debian bullseye main contrib non-free

#deb-src http://deb.debian.org/debian bullseye main contrib non-free

deb http://deb.debian.org/debian bullseye-updates main contrib non-free

#deb-src http://deb.debian.org/debian bullseye-updates main contrib non-free

deb http://deb.debian.org/debian bullseye-backports main contrib non-free

#deb-src http://deb.debian.org/debian bullseye-backports main contrib non-free

deb http://security.debian.org/ bullseye-security main contrib non-free

#deb-src http://security.debian.org/ bullseye-security main contrib non-free

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