Except the likes of GParted, df, udisks etc are exactly what I don't trust! I have read too many reports of people buying say a 128GB usb drive, copying loads of data onto it and later discovering everything after say 8 or 16GB isn't really there! Somehow they fake the part (ToC? MBR?) which the computer reads the size of the drive from and seems (at least in Doze-land, where most of these reports are from, but then again so is most the computer world) that the system even reports having written the files correctly and they show up in the table of contents and in your file explorer as you would expect. Hence I want to actually write data until the drive is near full and do an md5sum on the files I have written. It's only a single write of the few thousand they should be usable for and I plan to use them predominantly as back-up storage so I don't envisage lots of erase and re-writes over their lifetime. Basic drive integrity isn't a worry. Being sold dodgy, fake components which report the wrong size is.

I did wonder if doing something as simple as a full (rather than Quick) format to the likes of ext4 might catch out something like this too...

Dale.