我有一台 Vagrant 机器来运行 Symfony，它与 MySQL 数据库进行了很多交互。为了加快速度，我想为数据目录使用 tmpfs 文件系统。数据目录位于/var/lib/mysql，所以这是我尝试的：
1）停止mysql服务：sudo service mysql stop
2）挂载tmpfs：sudo mount -t tmpfs -o size=512M tmpfs /var/lib/mysql
3）启动mysql：sudo service mysql start
然后我收到以下错误：
Job for mysql.service failed. See "systemctl status mysql.service" and "journalctl -xe" for details.
systemctl status mysql.service输出是：
● mysql.service - MySQL Community Server
Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
Active: failed (Result: start-limit) since Tue 2016-04-05 20:30:52 UTC; 1min 58s ago
Process: 3376 ExecStartPost=/usr/share/mysql/mysql-systemd-start post (code=exited, status=0/SUCCESS)
Process: 3375 ExecStart=/usr/bin/mysqld_safe (code=exited, status=0/SUCCESS)
Process: 3839 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=1/FAILURE)
Main PID: 3375 (code=exited, status=0/SUCCESS)
Apr 05 20:30:52 libe systemd[1]: mysql.service holdoff time over, scheduling restart.
Apr 05 20:30:52 libe systemd[1]: start request repeated too quickly for mysql.service
Apr 05 20:30:52 libe systemd[1]: Failed to start MySQL Community Server.
Apr 05 20:30:52 libe systemd[1]: Unit mysql.service entered failed state.
Apr 05 20:30:52 libe systemd[1]: mysql.service failed.
哪个没有提供太多信息......关于如何调试这个或我做错了什么的任何想法？谢谢！