So I've followed a whole bunch of issues here for a good few hours and I wouldn't ask here if I wasn't completely out of ideas.

So today I came home to find my rpi3 unresponsive. It's running Stretch, with Kodi and a couple of hardrives as a media system. Only thing I could do was unplug it. When I did, I got the "Kernel panic-not syncing: VFS: unable to mount root fs on unknown- block(179,2)" error that is seemingly well documented. It's a relatively new install.

I go through the troubleshooting and attempt to go to recovery mode, but shift is not recognised. So I go to the next step which is to alter cmdline.txt. However, on my macbook it appears /boot is not writeable and nothing I do will make it so. So I;

  • Install osxfuse so I can see the other partitions (tho this is not actually needed), but it does show the partition is intact in diskutil
  • Attempt to remount the sd card as writeable, but still get permission denied.
  • Try another micro sd card in the adaptor to make sure it's not the sensor in my sd card reader that is not recognising the write protection being off. Other sd card writes fine

At this point I'm completely done. As soon as I can edit this cmdline.txt I can continue to troubleshoot but I just cannot mount this as writeable. Any ideas?

  • 1
    Sounds like a defective SD card. Copy the image to a new one and see if that helps. Feb 8, 2019 at 12:10

1 Answer 1


Your root filesystem on your SDCard partition #2 (/dev/mmcblk0p2 - device 179,2) is in need of a fsck and the system can't run that automatically.

You'll need a new SDCard, a copy of plain Raspbian and a USB SDCard reader. Or you'll need a laptop running Ubuntu or Mint that has an SDCard reader.

If doing it on a new SDCard, get Raspbian written to the new SDCard, boot that in your Raspberry. Mount the unbootable SDcard in your USB reader, mount your USB reader in your RPi

Open a command window and run

sudo -s
umount /dev/sda1
umount /dev/sda2
fsck -f -y /dev/sda1
fsck -f -y /dev/sda2

Swap the SDCard back and boot normally.

  • Thanks! Is it possible to run this in a linux vm perhaps? Feb 8, 2019 at 15:25
  • 1
    You can run it in any system that can read a EXT4 filesystem without barfing. Windows is the classic example of a system that will barf at a "not invented here" filesystem. If you can get the device attached to a Linux VM then you can use that to fix it.
    – Dougie
    Feb 8, 2019 at 16:20
  • Cheers, I'll give that a go Feb 9, 2019 at 0:55

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