在免费的 AMH 4.2面板上删除虚拟主机后，在VPS管理面板上仍然能看到被删除的虚拟主机目录（如test.com）。用PuTTY执行删除目录命令 rm -rf /home/wwwroot/test.com 提示 rm: cannot remove ‘…/tmp/mysql.sock’: Device or resource busy. 解决方法：先停止amh mysql, 再删除主机目录，最后开启amh mysql。PuTTY命令如下：
[root@vps]# rm -rf /home/wwwroot/test.com
rm: cannot remove `/home/wwwroot/test.com/tmp/mysql.sock': Device or resource busy
[root@vps]# amh mysql
=======================================================
[LNMP/Nginx] Amysql Host – AMH 4.2
http://Amysql.com
[AMH] MySQL Management please select: (1~6)
1) start 3) restart 5) force-reload
2) stop 4) reload 6) exit
#? 2
Shutting down MySQL. SUCCESS!
[OK] MySQL stop
[root@vps]# rm -rf /home/wwwroot/test.com
[root@vps]# amh mysql
=======================================================
[LNMP/Nginx] Amysql Host – AMH 4.2
http://Amysql.com
[AMH] MySQL Management please select: (1~6)
1) start 3) restart 5) force-reload
2) stop 4) reload 6) exit
#? 1
Starting MySQL. SUCCESS!
[OK] MySQL start