Ubuntu – Partitions lost trying to create bootable iso disk


I tried to create a bootable Ubuntu iso disk on a partition (sdc-2) of a usb stick, which had originally three partitions (sdc-1/2/3, of type ext3/fat32/ntfs). Following this thread, I ran:

sudo umount /dev/sdc2
sudo dd if=input.iso of=/dev/sdc

Now, I am not able to access the 3 partitions anymore. So first question, did I make a mistake? My feeling is that I should have used of=/dev/sdc2 instead, right?

Second question, how do I fix the problems:

  1. The partitions are not shown. Running testdisk, I see one "iso" partition, but then, the "quick search" option shows the three underlying partition. How can I get the three partitions system back?

  2. Previous partition sdc1 seems damaged. Testdisk detects it, but cannot list files. Did the dd operation irremediably damage it? Any change I could recover without using tools like photorecovery?

Thanks so much!!

Best Answer

did I make a mistake?

You overwrote the beginning of drive /dev/sdc with a ISO file. From the last part of your question, it seems it is not what you wanted to do. Hence yes, it was a mistake. A pretty bad one.

You should have used /dev/sdc2.

How can I get the three partitions system back?

As you have determined, you can easily restore the 2nd and the 3rd ones by using TestDisk.

TestDisk can create a partition table from the file systems it finds on your drive. The basic idea, however, is that you shoulde use TestDisk to copy the files on a different drive, then recreate your partitions from scratch.

You won't be able to do the same on the first one because it is damaged. You need to analyze /dev/sdc1 with an advanced recovery tool like R-Linux.

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