从供应商手中接手一个云平台（Windwos Azure）上的MySQL数据库，登录数据库时遇到错误：
$mysql -uroot -p
Enter password:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
检查配置文件/etc/my.cnf发现供应商修改了mysql数据库的数据存储目录，另外mysql.sock文件位置也变更为了/dat/data/mysql/mysql.sock
$ more /etc/my.cnf
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.6/en/server-configuration-defaults.html
[mysqld]
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
innodb_buffer_pool_size = 2048M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
#datadir=/var/lib/mysql
#socket=/var/lib/mysql/mysql.sock
datadir=/dat/data/mysql
socket=/dat/data/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Recommended in standard MySQL setup
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
检查发现/var/lib/mysql/mysql.sock文件不存在，可以通过建立mysql.sock文件的软连接。然后登录数据库，问题解决。
[root@GETAZLNX005 ~]# ls /var/lib/mysql/mysql.sock
ls: cannot access /var/lib/mysql.sock: No such file or director
[root@GETAZLNX005 ~]# ln -s /dat/data/mysql/mysql.sock /var/lib/mysql/mysql.sock