今天收到磁盘报警异常，50G的磁盘被撑爆了，分析解决过程如下：
1. 进入linux服务器，查看mysql文件夹中各个数据库所占的磁盘空间大小
看到了吗，光olderdb就占了25G
2. 用SQLyog登录mysql数据库，查看数据库各个表的占用空间情况
SELECT CONCAT(table_schema,'.',table_name) AS 'aaa', table_rows AS 'Number of Rows', CONCAT(ROUND(data_length/(1024*1024*1024),6),' G') AS 'Data Size', CONCAT(ROUND(index_length/(1024*1024*1024),6),' G') AS 'Index Size' , CONCAT(ROUND((data_length+index_length)/(1024*1024*1024),6),' G') AS'Total' FROM information_schema.TABLES WHERE table_schema LIKE 'olderdb';