win2008 R2因为管理员的设置问题，导致磁盘处于脱机状态 解决步骤：

　　使用Diskpart.exe的指令解除设置即可，过程为:

　　1.运行：cmd

　　2.输入：DISKPART.exe搜索

　　3.DISKPART> san

　　4.DISKPART> san policy=onlineall

　　5.DISKPART>list disk

　　6.DISKPART> select disk 1

　　7.DISKPART>attributes disk clear readonly

　　8.DISKPART>online disk

　　其解决方案的英文描述为：

　　open a command prompt and type “diskpart.exe”.

　　You will now receive a diskpart-prompt:

　　Diskpart>

　　Now type “san”. This will provide you with the current configured SAN policy:

　　SAN Policy : Offline Shared

　　In the diskpart-prompt, type “san policy=OnlineAll”.

　　This will result in the following message:

　　Diskpart successfully changed the SAN policy for the current operating system.

　　Now type “list disk”, which will give this message:

　　Disk ### Status Size Free Dyn Gpt

　　Disk 0 Online 30 GB 0 B

　　Disk 1 Offline 50 GB 1024 KB

　　In my case, disk 1 was offline so I typed “select disk 1” which provided:

　　Disk 1 is now the selected disk

　　Now type “attributes disk clear readonly”.

　　Disk attributes cleared successfully.

　　And to check if all the settings are now correct, type “attributes disk”.

　　This will give an output something like:

　　Current Read-only State : No

　　Read-only : No

　　Boot Disk : No

　　Pagefile Disk : No

　　Hibernation File Disk : No

　　Crashdump Disk : No

　　Clustered Disk : No

　　After the last check has been successful, type “online disk” to bring the disk online.