md5sum not match when dd the installtion DVD to a usb stick

Hi all,

I am trying to create a USB stick for installing openSUSE Tumbleweed on a new laptop with only Windows 10 pre-installed. I’ve read that in order to use UEFI method I need to “burn” the ISO file into a USB stick. Then I followed the instruction here:

Here is what I have done:

  1. Insert my USB thumb drive (32GB);
  2. Using fdisk to check its path to be /dev/sdb;
  3. cd into the folder hold the ostw.iso and issue the command,
sudo dd if=ostw.iso of=/dev/sdb bs=4k conv=fdatasync
  1. Issue following command to check md5sum after a long time waiting, but the given md5 value is not the same as that ISO file

Here is the USB drive in fdisk -l,

Device     Boot Start     End Sectors  Size Id Type
/dev/sdb1        3852   11663    7812  3.8M ef EFI (FAT-12/16/32)
/dev/sdb2  *    11664 9160703 9149040  4.4G 17 Hidden HPFS/NTFS

Could anyone please tell me what I have done wrongly? Cheers.

You did not show command used to verify md5sum; assuming you used device name (md5sum /dev/sdb) it won’t match, because /dev/sdb is much larger than ISO image, so md5sum will read past the end of image. I do not think there is easy way to verify checksum on USB device, unless you create loop over USB of exact image size.

Those instructions are for a raw image, not an iso;

Anyway, check the sha256 sum on the downloaded iso image, available from the same download location you obtained the iso image. Plus after you dd they will be different, you can do a media check on install, but if it’s ok on the iso image you should be fine.

Thanks arvidjaar,
You are right about the command I used to check MD5 sum. I used it on /dev/sdb. Thanks for pointing out the error.

Thanks Malcolm,
Sorry I am not aware of the difference between raw image and iso. Looks like I have made a big mistake. It’s the first time I am trying to create such a burned ISO. I’ll try to use this USB stick directly. It will work as per your explanation. Thanks!

… well, I would not call it a big mistake, but keep in mind: Mistakes are what we learn the most from. :wink:

Thanks for your encouraging words. I do have learnt a lot from this forums with the help of many experienced users.