mysql启动诡异，没错误日志看

现象mysql启动不了，也没有错误日志

[root@xxx ~]# /etc/init.d/mysqld  start
Starting MySQL.. ERROR! The server quit without updating PID file (/data/db/mysql/data/xxx.pid).
[root@xxx ~]# cat /data/db/mysql/data/xxx.err ##查看错误日志是空的

[root@xxx ~]# /data/soft/mysql/bin/mysqld --defaults-file=/data/soft/mysql/my.cnf --user=mysql --basedir=/data/soft/mysql/ 
2020-09-17T09:14:55.291853Z 0 [ERROR] InnoDB: Write to file ./ibtmp1failed at offset 0, 1048576 bytes should have been written, only 0 were written. Operating system error number 28. Check that your OS and file system support files of this size. Check also that the disk is not full or a disk quota exceeded.
2020-09-17T09:14:55.291867Z 0 [ERROR] InnoDB: Error number 28 means 'No space left on device'

有道翻译：InnoDB: Write to file ./ibtmp1failed at offset 0,1048576应该被写入，只有0被写入。操作系统错误号码28。检查您的操作系统和文件系统是否支持这种大小的文件。还要检查磁盘是否满或是否超过磁盘配额。
发现-磁盘没占满了。