[ERROR] Can't start server: can't create PID file:

今天mysql启不来了，说是创建不了pid,我就奇怪了，难道是权限的问题？ 看了看也不是啊，

后来一df 一下磁盘没空间了。

110525 15:41:46  InnoDB: Started; log sequence number 0 46409
110525 15:41:46 [ERROR] /usr/local/mysql/libexec/mysqld: Error writing file '/usr/local/mysql/var/apache3.ygy.com.cn.pid' (Errcode: 28)
110525 15:41:46 [ERROR] Can't start server: can't create PID file: No space left on device
110525 15:41:46 mysqld_safe Number of processes running now: 0
110525 15:41:46 mysqld_safe mysqld restarted

意思是说创建不了'/usr/local/mysql/var/apache3.ygy.com.cn.pid'   
No space left on device 没有磁盘空间了。