ubuntu20.04 apt update hash sum mismatch

outline

1 problem
2 resolve

1 problem

zzl@zzl-vm:~$ sudo apt update
hash sum mismatch

2 resolve

sudo apt clean
sudo rm -rf /var/lib/apt/lists/*
sudo nano /etc/apt/source.list

#增加以下内容
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-backports main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-security main restricted universe multiverse


sudo apt update

done.