换国内源：
PVE换源
wget https://mirrors.ustc.edu.cn/proxmox/debian/proxmox-release-bullseye.gpg -O /etc/apt/trusted.gpg.d/proxmox-release-bullseye.gpg
echo "#deb https://enterprise.proxmox.com/debian/pve bullseye pve-enterprise" > /etc/apt/sources.list.d/pve-enterprise.list
echo "deb https://mirrors.ustc.edu.cn/proxmox/debian/pve bullseye pve-no-subscription" > /etc/apt/sources.list.d/pve-no-subscription.list
Debian换源
mv /etc/apt/sources.list /etc/apt/sources.list.bk
nano /etc/apt/sources.list
Sources.list加入源
deb http://mirrors.ustc.edu.cn/debian stable main contrib non-free
# deb-src http://mirrors.ustc.edu.cn/debian stable main contrib non-free
deb http://mirrors.ustc.edu.cn/debian stable-updates main contrib non-free
# deb-src http://mirrors.ustc.edu.cn/debian stable-updates main contrib non-free
# deb http://mirrors.ustc.edu.cn/debian stable-proposed-updates main contrib non-free
# deb-src http://mirrors.ustc.edu.cn/debian stable-proposed-updates main contrib non-free
更新
apt update
apt upgrade -y