@construkt Nice. Well as far as I see it you can choose what ever NAS OS you want since a NAS primary goal is to serve files to clients such as computers on any network through file protocols such as SMB and NFS. It doesn't matter what OS the clients have or what NAS OS you decide to go with as long as both NAS OS and the clients OS supports the correct file protocols. And as @mitu says it is better to set up a data redundancy environment with RAID. This is also known as mirroring. Lets say you have 2x 2 TB hard drives added to a RAID Mirroring setup, both of the drives will be in the same hard drive volume and they are connected together so if one drive fails you will not lose any data, however this setup will have the cost of making only half of the disk space available. So instead of 4 TB total disk space it will only be 2 TB total but you will be protected if any power cut happens in your home. I have tried this from experience and on my point of view I only needed to buy a new hard drive to match the other to rebuild the volume again.

Please add more info about your system, as detailed in https://retropie.org.uk/forum/topic/3/read-this-first. The save file is done by RetroArch, which I haven't heard or see to work that (doesn't matter the which core is used).

@mitu All sorted now thanks.

I ve managed to do it through some commands. Thanks anyway! :)

Found the culprit. Please use Option 1 in the above mentioned wiki to include the roms from your NAS. Then it's working. It will not work with Option 2. Thanks. Leaving this for others, if they happen to get into the same issues.

Perfect, thanks for the replies! Another quick question, I can mount ext drives on my Mac, so I can edit files on the main retropie partition, with this in mind, is there anyway I can manually replace / edit scraped data? Some of the games I have scraped have the incorrect pictures or can't find data at all, so I would like to manually create / edit some of them. Is this possible, and if so, where are the files? Stewart

@enderandrew This isn't necessarily the case because some USB 2.0 flash drives are a lot slower than what the USB 2.0 standard allows in my experience. With A USB 3.0 flash drive, you will likely see performance much closer to the maximum USB 2.0 is capable of on the Pi as they are built for speed. I bought a low-profile USB 3.0 drive for this reason and in my case, throughput did not disappoint.