简单说明（E文水平有限，有误之处，请多指教）
# ./mysqltuner.pl --help
MySQLTuner 1.2.0 - MySQL High Performance Tuning Script
Bug reports, feature requests, and downloads at http://mysqltuner.com/
Maintained by Major Hayden (major@mhtx.net) - Licensed under GPL
Important Usage Guidelines:
To run the script with the default options, run the script without arguments
Allow MySQL server to run for at least 24-48 hours before trusting suggestions
#建议在MySQL服务器运行24-48小时，测试才有依赖性
Some routines may require root level privileges (script will provide warnings)
#对于越权的权限会报警
You must provide the remote server‘s total memory when connecting to other servers
#当连接其他服务器时，须提供远程服务器的总内存
Connection and Authentication#连接、认证
--host <hostname> Connect to a remote host to perform tests (default: localhost)
--socket <socket> Use a different socket for a local connection#通常在本机测试时使用
--port <port> Port to use for connection (default: 3306)
--user <username> Username to use for authentication
--pass <password> Password to use for authentication
Performance and Reporting Options#性能报告选项
--skipsize Don‘t enumerate tables and their types/sizes (default: on)
#不列举表名以及类型和大小，默认打开，推荐打开此选项
(Recommended for servers with many tables)
-------- Storage Engine Statistics -------------------------------------------
[--] Status: +Archive -BDB -Federated +InnoDB -ISAM -NDBCluster
[--] Data in MyISAM tables: 392K (Tables: 116)
[--] Data in PERFORMANCE_SCHEMA tables: 0B (Tables: 17)
[!!] InnoDB is enabled but isn‘t being used
[OK] Total fragmented tables: 0
--checkversion Check for updates to MySQLTuner (default: don‘t check)
#检查更新，加了该参数效果如下
#[OK] You have the latest version of MySQLTuner
#不加的话
#[--] Skipped version check for MySQLTuner script
--forcemem <size> Amount of RAM installed in megabytes
--forceswap <size> Amount of swap memory configured in megabytes
#设置物理内存和swap分区的大小（单位MB），这两个参数一般成对配置
#[--] Assuming 512 MB of physical memory
#[--] Assuming 1024 MB of swap space
Output Options:
#输出显示的参数试一下就清楚了
--nogood Remove OK responses
--nobad Remove negative/suggestion responses
--noinfo Remove informational responses
--nocolor Don‘t print output in color
例如
./mysqltuner.pl --socket /var/lib/mysql2/mysql2.sock
……
-------- Performance Metrics -------------------------------------------------
[--] Up for: 23h 37m 18s (542 q [0.006 qps], 176 conn, TX: 442K, RX: 33K)
下面是该程序给的一些修改建议，大家可参考修改。有时间的话，还可以用sysbench进行测试。
-------- Recommendations -----------------------------------------------------
General recommendations:
Add skip-innodb to MySQL configuration to disable InnoDB
MySQL started within last 24 hours - recommendations may be inaccurate
Reduce your overall MySQL memory footprint for system stability
Enable the slow query log to troubleshoot bad queries
Set thread_cache_size to 4 as a starting value
Variables to adjust:
*** MySQL‘s maximum memory usage is dangerously high ***
*** Add RAM before increasing MySQL buffer variables ***
query_cache_size (>= 8M)
thread_cache_size (start at 4)
本文出自 “Linux运维” 博客，请务必保留此出处http://2853725.blog.51cto.com/2843725/1394455