You can be stuck in this scenario where dynamic DG is faulted and your server volume is failed or stopped state. In this case you may also see another DG which is unknown DG which holds disks which are foreign.
Its importnat you should follow the steps very carefully as there are chances of data lose.
Now you can see the above image which shows the Group Name of the Disk but this Disk is out of the DG and shows as Foreign.
Ok now lets see how we can fix this…
You need to right click on the Disk and click Merge Foreign Disk
Click Yes and you see your DG is online and after that you need to right click on Volume and click reactive.
After these steps you should see your volume up and running status.