物理备份：

               SHOW VARIABLES LIKE'datadir';
                use hellodb;
                SHOW TABLE STATUS;
                mysql
             FLUSH LOGS WITH READ LOCK;
             \q
             lvcreate -L 50M -n mysnap -s /dev/myvg/mydata
             mysql     
             UNLOCK TABLES;
               \q
              mount /dev/myvg/mysnap /mnt
             cd /mnt
             cd data/
             ls
             tar -jcf /root/mysql.tar.bz2   hellodb ibdata1 ib_logfile* mysql-bin* 
            ls
            cd
             umount /mnt
              lvremove --force /dev/myvg/mysnap
             service mysqld start
              ls /mydata/data
             rm -rf  /mydata/data/*
              cd /usr/local/mysql
                 chown -R mysql:mysql data/ 
              scripts/          --datadir=/mydata/data --user=mysql
              killall mysqld
              service mysqld start
              service mysqld stop
                cd /mydata
                  cd data
                   ls
                   tar xf /root/mysql.tar.bz2 -C ./
                     ls
              service mysqld start
              mysql
              SHOW DATABASES;
增量备份：
            SHOW MASTER STATUS
             lvcreate -L 50M -n mysnap -s /dev/myvg/mydata
              mysql     
             UNLOCK TABLES;
              tar -jcf /root/mysql.tar.bz2   hellodb ibdata1 ib_logfile* mysql-bin* 
             mysql
             use hellodb;
                 INSERT INTO t2 values('huhu')
              SHOW MASTER STATUS;
               mysqlbinlog --start-position  201 mysql-bin.000004 >/root/mysql2.incr.sql
            cd
              serviece mysqld stop
              rm -rf /mydata/data/*
             cd /usr/local/mysql
                 chown -R mysql:mysql data/ 
              scripts/          --datadir=/mydata/data --user=mysql 
               service mysqld start
               serviece mysqld stop
                cd /mydata/data/
                tar xf /root/mysql.tar.bz2 -C ./    
                 service mysqld start
                 mysql
                 use hellodb;
                 SELECT * FROM t2;
                 #mysql                  mysql
                 use hellodb;
                 SELECT * FROM t2;