当试图在CentOS 6.5盒子上启动mysqld恶魔时，出现以下错误：
[root@hardin ~]# service mysqld start Another MySQL daemon already running with the same unix socket. Starting mysqld: [FAILED]
这很奇怪，因为服务没有启动（它被configuration为在默认端口上运行）：
[root@hardin ~]# service mysqld status mysqld is stopped
我不知道如何find导致问题的Unix套接字：
Active UNIX domain sockets (servers and established) Proto RefCnt Flags Type State I-Node Path unix 10 [ ] DGRAM 12056 /dev/log unix 2 [ ACC ] STREAM LISTENING 8720 @/com/ubuntu/upstart unix 2 [ ACC ] STREAM LISTENING 12878 /var/run/mcelog-client unix 2 [ ] DGRAM 9289 @/org/kernel/udev/udevd unix 2 [ ] DGRAM 12440 @/org/freedesktop/hal/udev_event unix 2 [ ACC ] STREAM LISTENING 12275 /var/run/dbus/system_bus_socket unix 2 [ ACC ] STREAM LISTENING 13128 /var/run/abrt/abrt.socket unix 2 [ ACC ] STREAM LISTENING 12415 @/var/run/hald/dbus-jQMFHN9EAI unix 2 [ ACC ] STREAM LISTENING 12408 @/var/run/hald/dbus-YQIZ9h7s4Q unix 2 [ ACC ] STREAM LISTENING 12371 /var/run/acpid.socket unix 2 [ ] DGRAM 14119 unix 3 [ ] STREAM CONNECTED 13579 /var/run/dbus/system_bus_socket unix 3 [ ] STREAM CONNECTED 13578 unix 2 [ ] DGRAM 13521 unix 3 [ ] STREAM CONNECTED 13493 unix 3 [ ] STREAM CONNECTED 13492 unix 2 [ ] DGRAM 13130 unix 2 [ ] DGRAM 13058 unix 2 [ ] DGRAM 13023 unix 2 [ ] DGRAM 12875 unix 2 [ ] DGRAM 12840 unix 3 [ ] STREAM CONNECTED 12773 /var/run/acpid.socket unix 3 [ ] STREAM CONNECTED 12772 unix 3 [ ] STREAM CONNECTED 12767 @/var/run/hald/dbus-YQIZ9h7s4Q unix 3 [ ] STREAM CONNECTED 12766 unix 3 [ ] STREAM CONNECTED 12716 @/var/run/hald/dbus-YQIZ9h7s4Q unix 3 [ ] STREAM CONNECTED 12634 unix 3 [ ] STREAM CONNECTED 12714 @/var/run/hald/dbus-YQIZ9h7s4Q unix 3 [ ] STREAM CONNECTED 12534 unix 3 [ ] STREAM CONNECTED 12435 @/var/run/hald/dbus-jQMFHN9EAI unix 3 [ ] STREAM CONNECTED 12434 unix 3 [ ] STREAM CONNECTED 12410 /var/run/dbus/system_bus_socket unix 3 [ ] STREAM CONNECTED 12409 unix 2 [ ] DGRAM 12375 unix 3 [ ] STREAM CONNECTED 12295 /var/run/dbus/system_bus_socket unix 3 [ ] STREAM CONNECTED 12294 unix 3 [ ] STREAM CONNECTED 12289 unix 3 [ ] STREAM CONNECTED 12288 unix 3 [ ] DGRAM 9308 unix 3 [ ] DGRAM 9307
我使用这个盒子作为Git服务器，运行GitLab，它曾经工作。 冷启动后，它不再工作，因为unicorn无法连接到MySQL的原因上面的原因：
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/mysql2-0.3.11/lib/mysql2/client.rb:44:in `connect': Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (111) (Mysql2::Error)
我想知道如何解决这个问题，并find什么服务在MySQL端口上运行。
您可以使用
lsof -U | grep -i mysql mysqld 28944 mysql 12u unix 0xffff88002cacb6c0 0t0 532368 /var/lib/mysql/mysql.sock mysqld 28944 mysql 29u unix 0xffff88002a724380 0t0 532402 /var/lib/mysql/mysql.sock
看看哪个进程（如果有）拥有套接字并采取适当的行动
如果您确定没有其他MySQL进程正在运行，您可以简单地删除/var/lib/mysql/mysql.sock文件。 当MySQL启动时，如果套接字不存在，它将重新创build它。