27th May 2020

Appliance Down! Emergency Mode! failed to start file system check

Appliance Down! Emergency Mode! failed to start file system check.

My lab had a little hi-cough the other day, I’d managed to fill the management vSAN partition… Never a good idea. Whilst I managed to recover space and bring VMs back online one VM greeted me with the following screen…

Luckily I’d seen this behaviour before and knew roughly what to do – something I was able to validate by reviewing this KB article. What follows are those instructions with my screenshots.

Reboot the virtual appliance and immediately after the OS starts, press e to open the GNU GRUB Edit Menu.
Locate the line that begins with the word linux.
Append the following to the end of that line:
```
systemd.unit=emergency.target
```
Press F10 to continue booting.
Find the filesystems by running the command:
```
:/# /bin/sh
:/# /bin/mount
```
```
:/# blkid
```
Note: You will see the list of devices mounted with the disk uuid.
Execute the command:
```
:/# e2fsck -y /dev/sda3
```
Now the article here expressly identifies sda3. However, I can see from the output of blkid that sda3 is swap so e2fsck will do nothing for me as e2fsck is used to check the ext2/ext3/ext4 family of file systems. Therefore I need to run the command against sda2 and sda4.

Note: The nodes will be fixed automatically as we have given -y.
Power off the virtual appliance.
Power on the virtual appliance.

All things being equal, the photon based appliance should now start as normal.

Thanks

Simon