This guide is for Debian 11 CLI on a KVM VPS (/dev/vda1).
Manual Optimization Steps
1.1 Minimal System
sudo apt update && sudo apt upgrade -y sudo apt autoremove --purge -y sudo apt clean
Remove unnecessary packages:
sudo apt remove --purge -y apport popularity-contest avahi-daemon cups rpcbind xserver-common x11-common
1.2 Kernel Optimization
sudo apt install -y linux-image-cloud-amd64 sudo sed -i 's/GRUB_CMDLINE_LINUX_DEFAULT="[^"]*/& mitigations=off noibrs no_stf_barrier/g' /etc/default/grub sudo update-grub
1.3 Network Optimization
Enable BBR:
echo "net.core.default_qdisc=fq" | sudo tee -a /etc/sysctl.conf echo "net.ipv4.tcp_congestion_control=bbr" | sudo tee -a /etc/sysctl.conf sudo sysctl -p lsmod | grep bbr
Improve DNS resolution:
sudo sed -i 's/#DNS=/DNS=8.8.8.8 1.1.1.1/g' /etc/systemd/resolved.conf sudo systemctl restart systemd-resolved
1.4 Security Optimization
Change SSH port:
sudo sed -i 's/#Port 22/Port 22022/g' /etc/ssh/sshd_config sudo systemctl restart ssh
1.5 Disk & CPU Optimization
sudo tune2fs -o journal_data_writeback /dev/vda1 sudo tune2fs -m 1 /dev/vda1 echo "vm.swappiness=10" | sudo tee -a /etc/sysctl.conf sudo sysctl -p echo "performance" | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
Now your Debian 11 VPS is optimized for performance and security! 🚀