今天下午我们的测试服务器上的数据库不知道怎么就挂掉了，
然后就一直启动不了
201018 20:13:23 mysqld_safe Starting mysqld daemon with databases from /opt/mysql
201018 20:13:29 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
201018 20:22:37 mysqld_safe Starting mysqld daemon with databases from /opt/mysql
201018 20:22:43 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
201018 20:29:01 mysqld_safe Starting mysqld daemon with databases from /opt/mysql
201018 20:29:08 mysqld_safe mysqld from pid file /var/lib/mysql/mysqld.pid ended
201018 20:30:28 mysqld_safe Starting mysqld daemon with databases from /opt/mysql
201018 20:30:34 mysqld_safe mysqld from pid file /var/lib/mysql/mysqld.pid ended
一直报这个错误；
尝试了3个办法：
1、查了一下 mysqld.pid 确实不存在，手动touch一个把读写权限都给出来，启动时会自己删除掉
把pid目录指向 修改后，还是启动报错，启动不成功
2、执行mysqld_safe
也是一样报错
[root@iZuf6hbcmowi6ktvho935eZ mysql]# mysqld_safe
201018 21:35:26 mysqld_safe Logging to '/var/log/mysqld.log'.
201018 21:35:26 mysqld_safe Starting mysqld daemon with databases from /opt/mysql
/usr/bin/mysqld_safe: line 166: 27607 已杀死 nohup /usr/sbin/mysqld --basedir=/usr --datadir=/opt/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --log-error=/var/log/mysqld.log --open-files-limit=20000 --pid-file=/var/lib/mysql/mysqld.pid --socket=/opt/mysql/mysql.sock --port=13306 < /dev/null >> /var/log/mysqld.log 2>&1
201018 21:35:32 mysqld_safe mysqld from pid file /var/lib/mysql/mysqld.pid ended
在线求解，求提示
网上也查了一些帖子
1、说是内存原因，调整内存配置，但我在服务器上把其他应用停掉，16G内存服务器只留这个mysql，也启动不起来
2、删除$data_dir目录下的ib_logfile0.... 等等这几个文件，启动不起来
好无奈，只能重装了吗？ 测试数据要没有了
