optimize.sh

#!/bin/bash

# Check root privileges
if [ "$EUID" -ne 0 ]; then
  echo "Error: Run as root."
  exit 1
fi

# Backup current config
cp /etc/sysctl.conf /etc/sysctl.conf.bak

# Calculate total memory in GB
MEM_TOTAL_KB=$(awk '/MemTotal/ {print $2}' /proc/meminfo)
MEM_TOTAL_GB=$((MEM_TOTAL_KB / 1024 / 1024))

# Default: High performance (>8GB RAM)
RMEM_DEFAULT=16777216
WMEM_DEFAULT=16777216
RMEM_MAX=67108864
WMEM_MAX=67108864
TCP_RMEM="4096 87380 67108864"
TCP_WMEM="4096 65536 67108864"
NETDEV_BACKLOG=250000
SYN_BACKLOG=8192

# Dynamic allocation based on RAM
if [ "$MEM_TOTAL_GB" -lt 2 ]; then
    # Conservative (<2GB RAM)
    RMEM_DEFAULT=262144
    WMEM_DEFAULT=262144
    RMEM_MAX=4194304
    WMEM_MAX=4194304
    TCP_RMEM="4096 87380 4194304"
    TCP_WMEM="4096 65536 4194304"
    NETDEV_BACKLOG=30000
    SYN_BACKLOG=1024
elif [ "$MEM_TOTAL_GB" -lt 8 ]; then
    # Balanced (2GB-8GB RAM)
    RMEM_DEFAULT=2621440
    WMEM_DEFAULT=2621440
    RMEM_MAX=16777216
    WMEM_MAX=16777216
    TCP_RMEM="4096 87380 16777216"
    TCP_WMEM="4096 65536 16777216"
    NETDEV_BACKLOG=100000
    SYN_BACKLOG=4096
fi

# Write configuration
cat > /etc/sysctl.conf << EOF
# Dynamic sysctl config (RAM: ${MEM_TOTAL_GB}GB)
net.ipv4.ip_forward = 1
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1

net.core.rmem_default = ${RMEM_DEFAULT}
net.core.wmem_default = ${WMEM_DEFAULT}
net.core.rmem_max = ${RMEM_MAX}
net.core.wmem_max = ${WMEM_MAX}
net.ipv4.tcp_rmem = ${TCP_RMEM}
net.ipv4.tcp_wmem = ${TCP_WMEM}
net.core.netdev_max_backlog = ${NETDEV_BACKLOG}
net.ipv4.tcp_max_syn_backlog = ${SYN_BACKLOG}

net.core.default_qdisc = fq
net.ipv4.tcp_congestion_control = bbr
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_slow_start_after_idle = 0

net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_keepalive_time = 600
net.ipv4.tcp_keepalive_intvl = 60
net.ipv4.tcp_keepalive_probes = 5
EOF

# Apply changes
sysctl -p