File System / Folder Structure: GW5508NPG

[T S]

I upgraded my GW5508NPG firmware from 11/2019 to 8/2021.  Afterward, the system tells me I have no video data and the disk shows "unformatted".  I immediately unplugged the NVR.  I called Tech Support and they said this was a rare event but could not help.

I am attempting to forensically recover the much-needed video from the disk.  Can someone please tell me what OS, file system, folder structure and file format GW Security uses for its video file storage system?

Also, if you have a good suggestion for good data recovery software, that would be  appreciated.

Thank you,

Terry