While browsing in Aldi noticed a 1TB usb3 storage drive reduced by £20.00 to £60.00. Although you could probably make your own a bit cheaper the neat black enclosure looks good by the side of FOX T2. Duly purchased same.
First job was to connect the existing drive to my laptop to look at the file structure. I used LinuxReader to examine the drive.
A very simple single partition structure is revealed. Just two folders and a single file in the root of the drive
Folders .tsr and Video (presumably the .tsr contains the time shift buffer file - mental note to investigate further :-))
Single file epgsavedata.
I copied the contents of the Video folder to a temporary folder on a ntfs drive on my laptop.
Connected the new drive to the FOX T2 and elected to format it (the original FS was FAT32). Big mistake - 5hrs later still indicating writing to drive. Powered everything off and connected the drive to my PC - still a FAT32 FS.
Did what I should have done in the first place, booted up EASUS Partition Manager (the free version) elected to delete the partition and format EXT3 (takes about 10 - 15 minutes to complete).
Connected the now EXT3 usb drive to the FOX-T2 and elected to format. About 5 minutes later format completed and elected to use the drive as the recording device.
At this stage the VIDEO folder does not exist, fixed by making a 1 minute instant recording.
Transfered the drive back to the PC and mounted the drive read/write using EXT2FS and copied the contents of the archived VIDEO folder back to the usb drive VIDEO folder.
Success all my original recordings intact.
Hope this helps anyone contemplating fitting a larger archive drive