I have recently bought a new ssd of 120 GB, and I ended up format it to FAT filesystem, then later I flashed raspbian jessie onto it. Everything went well and is booted from SSD until I hit expand filesystem that messed up OS installation.

Then I put back my old SD card and and booted from it. With SSD connect ed to USB , I went /boot folder on USB SSD It was empty. And SSD is identified as fat when booted from SD Card. The question is does formatting SSD with FAT is okay or acceptable? Or formatting SSD to ext4 would have made more sense which could have helped filesystem expansion?

  • depends on how you flashed raspbian jessie onto it - if you wrote the jessie (why so old) image onto it, then it should've had two partitions, a small FAT and a larger ext4 - how the disk was "originally" formatted is irrelevant - in fact, when using a raspbian image, you don't even need to format the SSD at all Dec 26, 2018 at 0:05
  • I used a tool called etcher to flash raspbian . Dec 26, 2018 at 0:09
  • then the original "format" is irrelevant - the /boot folder on the SSD would be on the second (ext4) partition, and should be empty, because that's where the first (FAT) partition is mounted on boot. As long as the SSD has two partitions (which you confirmed in your previous question) then there is no issue with the image written to the SSD Dec 26, 2018 at 0:18
  • I would recommend you start from the beginning, and follow the advice given in the answer to your previous question by tobyd Dec 26, 2018 at 0:20
  • and I think I see the source of your confusion - there are two partitions on raspbian ... first is a small FAT boot partition, and the second is the bulk ext4 partition - the image you made in your previous question you state that sda1 is the wrong size - it's not, it's the correct size for a boot partition Dec 26, 2018 at 0:24

1 Answer 1


If you write an image it does a block copy - so the original content is irrelevant - just another un-necessary write cycle.

Incidentally having an image copy on the original (with the same PARTUUID) is a recipe for disaster.

Use the SD Copy tool in the GUI making sure the SSD is UNMOUNTED first.

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