TL;DR: Use parted rescue

The Problem

Last Sunday evening, I accidentally deleted the partitions of my laptop while it was running. Initially, I wanted to remove all partitions from an SD card and create a single partition spanning the whole card. Absent-mindedly I went

... sudo parted /dev/sda ... rm 1 ... rm 2 ... rm 3 ...
... mkpart ... 0% ... 100% ... quit ...


Later that evening, when I restarted the computer, I realized what I did. /dev/sda was the internal disk of my laptop. I hadn’t even thought about which device the SD card was. The correct device would have been /dev/mmcblk0. Maybe tab-completion was doing its part: I probably did sudo parted /dev/sd<TAB><TAB> to see which disks are there, but it automatically completed it to sda after the first <TAB>.

Ok, I’ve screwed up. How to fix this? Luckily, I didn’t format the new partition. I wanted to let my digital camera do the job. (How should I know what file system it needs: fat? fat32? exfat? ntfs?) However, not formating the new partition is key here. During my self-destruct parted-session, I deleted the partitions from the partition table. But still, it should have left the rest of the disk untouched, including the actual contents of the partitions, the file systems, and all my data. Theoretically, I only need to recreate the same partitions with the exact same sizes, and everything should be back to normal (without using a backup).

The Solution

parted was my enemy here, but as it turns out, parted is also your best friend when you want to restore deleted partitions. When you boot a live Linux system from a USB stick, you can operate on the fried disk with parted.

The task is to recreate the same partitions. Well, I didn’t remember the exact sizes and positions of my partitions. (Should I keep a copy of my partition table in my wallet since I don’t like to pay attention when I work with parted?)

You could try to at least match the beginning of the partitions and ask the contained file system how large it is. However, there is a much easier way. parted ships with the rescue command. The rescue command asks for rough limits were the beginning of a partition was and scans the space for magic blocks and file system headers. When it finds something, it directly asks whether it should recreate the previous partitions. See

Within 2 minutes, everything was back to normal.