backup 的启动 .............................................................................. 16 4 Heartbeat 高可用 Mysql 主主同步方案 .............................................................................. ........................ 17 4.5.5 Heartbeat 的配置 .......................................................................................... 18 4.5.6 Heartbeat 的启动 ................................ ...................................................................................... 19 5 Heartbeat+DRBD+mysql 高可用方案 ..............................................................................