# 修改密码
passwd

# 修改端口
nano /etc/ssh/sshd_config
systemctl restart sshd

# 释放 Linux 系统预留的硬盘空间
tune2fs -m 1 路径

# 安装cloud内核
apt update
apt install linux-image-cloud-amd64
update-grub
reboot
# 删除过时的内核：
dpkg --get-selections | grep linux
apt autoremove --purge 内核名称
apt autoremove
apt autoclean
# 清理一下
rm -rf /var/lib/apt/lists/*   /var/cache/apt

# 开启BBR
echo "net.core.default_qdisc=fq" >> /etc/sysctl.conf
echo "net.ipv4.tcp_congestion_control=bbr" >> /etc/sysctl.conf
sysctl -p
# 查看状况
sysctl net.ipv4.tcp_available_congestion_control
lsmod | grep bbr