mysql主从同步抛出异常：

Last_Error: Error 'File './law/sales.MYD' not found (Errcode: 24)' on query. Default database: 'law'. Query: 'UPDATE law.sales SET usertyp='6', qqnu='', mobil='', phon='', areacod=',150000,150100,150101,150102,150103,150104,150105,150106,150107,150108,150109,150110,150112,150113,150114,150115,150116,150117,150118,150200,150201,150202,150203,150204,150205,150206,150207,150208,150209,150210,150211,150212,150213,150214,150215,150300,150301,150302,150303,150304,150305,150306,150307,150308,150309,150310,150311,150312,150313,150314,150315,150316,150317,150700,150701,150702,150703,150704,150705,150706,150707,150708,150709,150800,150801,150802,150803,150804,150900,150901,150902,150903,150904,150905,150906,150907,150908,150909,150910,150911,150912,150913,150914,151100,151101,151102,151103,151104,151105,151106,151107,151108,151109,151110,210000,210500,210501,210502,210503,210504,210505,210506,210507,210508,210600,210601,210602,210603,210604,210800,210801,210802,210803,210804,210805,210806,

Skip_Counter: 0

直接的处理方法：

重启从数据库，这样就可以执行过去。因为刚启动的时候是不会超过文件限制的。

系列分析命令：

用perror工具查看具体错误:

[root@workserv bin]# pwd

/usr/local/mysql/bin

[root@workserv bin]# ./perror 24

OS error code  24:  Too many open files

错误为超出最大打开文件数限制。

查看系统的最大打开文件数： 65535不存在超出的可能。

[root@workserv1 bin]# ulimit -n

65535

查看数据库的最大打开文件数的限制：

mysql> show variables like 'open_files_limit';

+------------------+-------+

| Variable_name    | Value |

+------------------+-------+

| open_files_limit | 4156  |

+------------------+-------+

如果这个值太小不够用，可以设置足够大 ， 修改 my.cnf

open_files_limit = 8000

另外可以查看当前打开的文件数：

mysql> show status like '%Open_files%';

+---------------+-------+

| Variable_name | Value |

+---------------+-------+

| Open_files    | 473   |

+---------------+-------+

1 row in set (0.00 sec)

mysql 引擎： myisam根据架构，每查询一个表需要打开两个文件及使用两个文件句柄，类推查询使用到多少个表就要使用2倍于多少个文件句柄。

*.frm   *.MYD   *.MYI

系统的修正限制打开文件数方法：使用 sysctl

[root@xxx]# sysctl -w fs.file-max=43621

[root@xxx]# sysctl -a | grep fs.file-max

fs.file-max = 43621