Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I want to write a .raw file to the first partition of my external drive. I tried: dd if=file of=/dev/sdb3 but it didn't give me a bootable drive since the correct command should had been: dd if=file of=/dev/sdb.

My question is would this command destroy data on the other two partitions that I have on the drive, or only on the first partition?

share|improve this question
To answer your question it's essential to know how you have created the .raw file. B/w, you have already destroyed data on the third partition - /dev/sdb3. – Pavel A Dec 25 '12 at 19:37
I downloaded it from the internet. I'm trying to install the Chrome OS. Now I'm trying to copy it to the first partition on my external hard drive (/dev/sda3) and install the Chrome OS off of it... – Maputo Dec 25 '12 at 19:39
Ignacio is absolutely right, but I still can't get how /dev/sda3 is the first partition of your external hard drive. – Pavel A Dec 25 '12 at 19:44
I'm sorry, I meant sdb3. I used gparted to create the partition by moving the data and shrinking the previous partition, so it got the number 3, I guess because 1 and 2 wew already taken – Maputo Dec 25 '12 at 19:48
okay, now I see. – Pavel A Dec 25 '12 at 19:55
up vote 3 down vote accepted
  1. It would destroy the partition table, since that's stored at the beginning of the drive.

  2. It would destroy as much drive contents as the size of the image itself. If it is large enough to reach into the second or third partitions then it will destroy those.

  3. MEMDISK will allow you to leave it as an image and boot it directly.

share|improve this answer
So there is not way that it could reach the second partition because the .raw image is not so large. But if my partition table gets destroyed, what does it mean? Is the data on the other partitions lost? – Maputo Dec 25 '12 at 19:45
No, but you'll need to reconstruct the partition table before you can access them. I recommend using fdisk -l on the drive and copying down the information before doing anything else. – Ignacio Vazquez-Abrams Dec 25 '12 at 19:50

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.