Did you remember to partition the card and format as ext4 ?
When I created my ubuntu image, I used a single ext4 partition; this is much simpler and easier than using two partitions.
See my create EspressoBIN ubuntu image for how an image could be created.
… You can use my imageWriter script for writing the image conveniently to a SD-card or USB-stick.
(In this case, you want to write to a block-device, not a single partition, because the EspressoBIN.img file is a volume that contains partitions).
Note: I use cp instead of dd, this is only for convenience; the outcome is identical.
Note2: Some people fear using dd, because they’re afraid of losing all their data, but dd is not a dangerous tool at all, this is a complete misunderstanding. ‘dd’ is just as harmless as cp, cat echo, printf and so forth, but if you write to anything in /dev, you want to be careful – no matter which command you use.
My goal with those scripts is to make it easier and safer to write disk images.
