I accidentally run dd if=image.img of=/dev/sda instead of /dev/sdb and sda is my main partition. When i realised i misstyped it i immediately stopped the process with CTRL+C, so it run only for like 2 seconds. When i rebooted i couldnt boot to any partition, the UEFI boots on the bios boot menu was empty. I created a live image of the Gparted live and run a testdisk and it found 4 out of the 6 partitions that i had, the efi partition was on sda2 and now its on sda1, windows part from sda4 to sda2 and linux and linux swap from sda5 and sda6 to sda3 and sda4. Despite that the efi partition still exists with the EFI folder in it and some entries inside when i run efibootmgr i cant see any entry and when i run manjaro live on UEFI it said that it cant find efi. So what i want to do is to be able to boot to the os's again or at least at windows(because i will reinstall linux and windows have some files that i want). Any help is apreciated, thanks for your time :) !

  • Windows typically has multiple partitions. Pretty sure testdisk cannot find the 128MB unformatted required system reserved partition (MSR) that must be before the main partition. Testdisk should have found a recovery partition at beginning of drive if ESP was sda2. docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/… Do you have any documentation/backup of partition table info? askubuntu.com/questions/665445/…
    – oldfred
    Commented Feb 11, 2020 at 17:04
  • No, i only remember that before it was like this: - sda1: recovery - sda2: EFI - sda3: (dont remember but it was less than a GiB) - sda4: Windows - sda5: Linux - sda6: Linux Swap now its like this: - sda1: efi - sda2: windows - sda3: linux - sda4: linux swap
    – Panos Trak
    Commented Feb 12, 2020 at 10:48

2 Answers 2


Even 2 sec, at least the beginning 300MB of your disk is rewritten. You may not be able to correctly boot into your MS-Windows because you need not only the EFI, but also the MS-Windows boot-manager. What I recommend is while working on some other OS even other computer: download some live Linux (I preffere CAINE) create the boot USB flash disk (or burn the DVD). Start your damaged computer from the CAINE, look for files you need to save and copy them to some other media (do not forget to unlock the target disk for write - the CAINE is very strict).

The more expensive way is to buy a new harddisk to install your Linux on it, and then you can mount some partitions from your corrupted disk under the Linux. For easy working with NTFS (MS-Windows default filesystem) you need to install some Linux utilities like parted, gparted, ntfs-3g, etc.

Under Linux you may mount a partition even the MBR/EFI partition table does not exist. Simply you have to find the begining of the partition (e.g. by looking for NTFS string) and if you know the exact offset form the beginning of the disk you can mount it by:

mount /dev/sdX /mnt/windows -o ro,loop,offset=xxxx 

On the other hand, after you successfully install the Linux, you may try to configure the Grub bootloader to identify your original MS-Windows partition and to add it into it's boot list.

  • 1
    Ok because i think the disk is corrupted, what am thinking is wiping the disk but if i move the files that i want to another media (like external hd) is it possible to wipe the entire disk like a fresh one and install windows and linux again?
    – Panos Trak
    Commented Feb 11, 2020 at 10:49
  • Definitely yes. But in fact it is not necessary, because in the time of the installation at least the 10 - 20 GB will be overwritten by new data. What we recommend is to be carefull. The temerity is very dangerous.
    – schweik
    Commented Feb 11, 2020 at 11:40
  • What installation and what 10-20GB?
    – Panos Trak
    Commented Feb 11, 2020 at 12:09
  • I prefere Debian Linux with KDE, but you can install (K)Ubuntu , etc. On web pages of debian.org or ubuntu.com or kubuntu.org you can find tutorial what to download and how to install.
    – schweik
    Commented Feb 11, 2020 at 20:16
  • I cant understand you, i will install Manjaro+i3 and i know how to install but first i need to fix the drive! I came with the conclusion to wipe the entire disk and reinstall windows and linux from scratch! :)
    – Panos Trak
    Commented Feb 11, 2020 at 21:24

First, make an image of what's left and if possible copy that image once more; then you can at least revert to the "bad but not hopeless" situation you've got already. Then consider what's less effort and most probably that will be to extract your data from partitions not affected and to install the OSes clean (wipefs -a /dev/sda first). efibootmgr shows what's stored in NVRAM, see also Rod's book on the topic (my favourite UEFI link :-).

  • What do you mean by make an image of what's left and if possible copy that image once more ?
    – Panos Trak
    Commented Feb 11, 2020 at 11:11
  • I mean dd if=/dev/damaged of=/external/disk/damaged.img bs=1M if you have an external drive with enough space to make a full drive image; having a copy of that file would enable you to perform data recovery attempts on a drive image instead of drive itself (when a slightest mistake or typo can make recovery harder yet or even impossible), helps a lot when you can experiment and learn over the course of it. BTW, I've started en.altlinux.org/rescue project for a reason having had quite a few data recovery sessions... (a text-only rescue livecd) Commented Feb 12, 2020 at 12:46
  • 1
    Thanks for your help but i decided to copy my files to an external ssd then wipe the whole disk with a live image and install windows and linux again from scratch :) btw what does wipefs do? i read something about wiping the signatures, do i need it or only dd if=/dev/zero will do the job?
    – Panos Trak
    Commented Feb 12, 2020 at 13:51
  • wipefs -a blows away all filesystem or e.g. MD RAID metadata off a given block device so that it's considered "clean" for future operations like mkfs or mdadm --create; these can sit at both start and end of the block device, the latter case would need some offset calculations for dd. Commented Feb 17, 2020 at 18:27

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