mysqld不要启动，因为没有进程，也没有日志。
SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)
运行mysqld start （以 root 身份）
151025 14:52:07 [Warning] Using unique option prefix key_buffer instead of key_buffer_size is deprecated and will be removed in a future release. Please use the full name instead.
151025 14:52:07 [Note] mysqld (mysqld 5.5.44-0ubuntu0.14.04.1) starting as process 1652 ...
并与--verbose它的回报相同。
当然，我检查了日志，但没有日志。
谢谢