Does anybody else fill USB sticks full of data? I have a backup regime currently based on 32GiB sticks, and I find it can take up to around 8 hours to fill one with files. (USB 3 sticks might have been a bit quicker, maybe half that time). So I tried an alternative approach: use dd to copy the stick to an image file, do a loopback mount of that image file, do the backup copy to the mounted image, dismount it, then use dd to copy it back to the actual stick. Time taken: typically less than 10 minutes to copy the stick to an image file, and up to an hour to copy the image file back to a USB 3 stick, or around 3 and a half hours for a USB 2 stick. The backup to the image file itself took an hour at most. Overall, still a substantial saving in time using the image-file approach. Doing a restore from the sticks is fast enough that I do this directly from them, without bothering with intermediate image files. Also I notice quite a variation in the actual capacities of the sticks. They are all nominally 32GiB = 2 ** 35 bytes, but the sizes of the usable partitions range from 89.5% of this to 91.4% -- well short of what it says on the tin. Even if you say it’s supposed to be 32GB = 32 * 10 ** 9 bytes, capacities range from 96.1% to 98.1% of the nominal value.