232 lines
5.5 KiB
Bash
232 lines
5.5 KiB
Bash
#!/usr/bin/env bash
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# Linux 交换文件管理脚本
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# 描述: 在 Linux VPS 上添加或删除交换文件
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set -euo pipefail # 遇到错误、未定义变量、管道失败时退出
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# 颜色定义
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readonly RED='\033[0;31m'
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readonly GREEN='\033[0;32m'
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readonly YELLOW='\033[1;33m'
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readonly NC='\033[0m' # 无颜色
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# 配置项
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readonly SWAPFILE="/swapfile"
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readonly SCRIPT_NAME="$(basename "$0")"
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# 日志输出函数
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log_info() {
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echo -e "${GREEN}[信息]${NC} $*"
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}
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log_warn() {
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echo -e "${YELLOW}[警告]${NC} $*"
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}
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log_error() {
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echo -e "${RED}[错误]${NC} $*" >&2
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}
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# 检查是否以 root 权限运行
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check_root() {
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if [[ $EUID -ne 0 ]]; then
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log_error "此脚本必须以 root 权限运行！"
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log_info "请使用: sudo $SCRIPT_NAME"
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exit 1
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fi
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}
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# 检查系统是否支持交换文件（非 OpenVZ）
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check_virtualization() {
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if [[ -d "/proc/vz" ]] && [[ ! -d "/proc/bc" ]]; then
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log_error "OpenVZ 容器不支持交换文件！"
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exit 1
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fi
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}
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# 验证交换文件大小输入
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validate_swap_size() {
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local size="$1"
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if ! [[ "$size" =~ ^[0-9]+$ ]] || [[ "$size" -lt 64 ]]; then
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log_error "无效的交换文件大小。必须是数字且 >= 64 MB"
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return 1
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fi
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# 检查可用磁盘空间
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local available_space
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available_space=$(df / | awk 'NR==2 {print int($4/1024)}')
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if [[ "$size" -gt "$available_space" ]]; then
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log_error "磁盘空间不足。可用: ${available_space}MB，需要: ${size}MB"
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return 1
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fi
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return 0
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}
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# 获取系统内存大小
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get_memory_size() {
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awk '/MemTotal/ {print int($2/1024)}' /proc/meminfo
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}
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# 检查交换文件是否已存在
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swap_exists() {
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grep -q "$SWAPFILE" /etc/fstab 2>/dev/null
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}
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# 显示当前交换文件信息
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show_swap_info() {
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log_info "当前交换文件信息："
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if [[ -f /proc/swaps ]]; then
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cat /proc/swaps
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fi
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echo
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grep "Swap" /proc/meminfo || true
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}
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# 添加交换文件
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add_swap() {
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if swap_exists; then
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log_error "交换文件已存在！"
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log_info "请先使用选项 2 删除现有的交换文件"
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return 1
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fi
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local memory_mb
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memory_mb=$(get_memory_size)
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local suggested_size=$((memory_mb * 2))
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echo
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log_info "当前系统内存: ${memory_mb}MB"
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log_info "建议交换文件大小: ${suggested_size}MB (内存的2倍)"
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echo
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read -rp "请输入交换文件大小（MB），直接回车使用建议值 ${suggested_size}MB: " swap_size
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swap_size=${swap_size:-$suggested_size}
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if ! validate_swap_size "$swap_size"; then
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return 1
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fi
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log_info "正在创建 ${swap_size}MB 交换文件..."
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# 使用更高效的方式创建交换文件
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if command -v fallocate >/dev/null 2>&1; then
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fallocate -l "${swap_size}M" "$SWAPFILE"
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else
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dd if=/dev/zero of="$SWAPFILE" bs=1M count="$swap_size" status=progress
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fi
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# 设置正确的权限
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chmod 600 "$SWAPFILE"
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# 设置交换文件
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mkswap "$SWAPFILE"
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swapon "$SWAPFILE"
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# 添加到 fstab 以实现持久化
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echo "$SWAPFILE none swap sw 0 0" >> /etc/fstab
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log_info "交换文件创建成功！"
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echo
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show_swap_info
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}
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# 删除交换文件
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remove_swap() {
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if ! swap_exists; then
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log_warn "未找到需要删除的交换文件"
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return 0
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fi
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log_info "正在删除交换文件..."
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# 关闭交换
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if swapon --show | grep -q "$SWAPFILE"; then
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swapoff "$SWAPFILE"
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fi
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# 从 fstab 中移除
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if grep -q "$SWAPFILE" /etc/fstab; then
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sed -i "\|$SWAPFILE|d" /etc/fstab
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fi
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# 删除交换文件
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if [[ -f "$SWAPFILE" ]]; then
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rm -f "$SWAPFILE"
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fi
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# 清理缓存
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sync
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echo 3 > /proc/sys/vm/drop_caches 2>/dev/null || true
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log_info "交换文件删除成功！"
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echo
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show_swap_info
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}
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# 显示菜单
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show_menu() {
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clear
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cat << 'EOF'
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╔══════════════════════════════════════╗
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║ Linux 交换文件管理 ║
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╠══════════════════════════════════════╣
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║ 1. 添加交换文件 ║
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║ 2. 删除交换文件 ║
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║ 3. 显示交换文件信息 ║
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║ 4. 退出程序 ║
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╚══════════════════════════════════════╝
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EOF
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echo
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}
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# 主菜单循环
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main_menu() {
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while true; do
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show_menu
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read -rp "请选择操作 [1-4]: " choice
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echo
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case "$choice" in
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1)
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add_swap
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;;
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2)
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remove_swap
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;;
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3)
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show_swap_info
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;;
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4)
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log_info "再见！"
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exit 0
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;;
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*)
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log_error "无效选择。请输入 1-4"
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sleep 2
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continue
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;;
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esac
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echo
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read -rp "按回车键继续..."
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done
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}
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# 主函数
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main() {
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# 执行系统检查
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check_root
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check_virtualization
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# 启动主菜单
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main_menu
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}
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# 脚本入口点
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if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
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main "$@"
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fi |