Gfilui

I've was trying to download some apps, notably nodejs in 17.04, when I realized the version had become discontinued. I updated to 17.10 (it seemed to restart abruptly for no reason) but the OS would no longer boot. GRUB was working, but as soon as I logged in I would get kicked back into the login screen.

So I got 17.10 on a USB and tried to install over the old partition, the setup had detected this and offered to preserve my previous data (I'm dual booting with windows). However, the setup got stuck pretty early into the setup while deleting the old OS files. I had left it for hours (usually this step takes seconds) and there was no way to exit, so I had no choice but to force shut down.

Now the installation doesn't detect the old installation anymore (it was partially successful I suppose), but my files are stuck. When I navigate to the partition I see the

 THIS DIRECTORY HAS BEEN UNMOUNTED TO PROTECT YOUR DATA.

From the graphical desktop, click on:
 "Access Your Private Data"

or

From the command line, run:
 ecryptfs-mount-private

but there is no option to open the terminal, and I can't seem to find a way to authenticate myself (because the old OS is partially deleted I suppose). How can I either a) Fix the installation and preserve the data or b) Get access to the locked data in order to do a clean install?

EDIT: When I try to launch the command ecryptfs-mount-private, for example in the home directory of the old OS, I get the error ERROR: Encrypted private directory is not setup properly

Thank you!

Okay, I have found a way to recover the data from a live USB, however its a little nuanced so I thought I'd share the solution, because I was ready to give up my data due to what is seemingly a bug.

First of all mount the partition with the encrypted files.

If

ecryptfs-recover-private

can't find the encrypted data by itself, run

sudo ecryptfs-recover-private /media/ubuntu/[unnecessary amounts of
letters and numbers]/home/.ecryptfs/[user name]/.Private

Follow the prompts to recover the directory. Since I didn't know the mount passphrase it asked to unwrap it using the login password.

At this point you will get one of two errors:
-5 means the password you entered is incorrect. If you see something like

Inserted auth tok with sig [f4f634c04c3cf3bf] into the user session keyring
mount: /tmp/ecryptfs.XciZjiT0: mount(2) system call failed: No such file or directory.
ERROR: Failed to mount private data at [/tmp/ecryptfs.XciZjiT0]

the password you entered was correct, but ecryptfs fails to mount the directory. This turns out to be some sort of bug detailed here:

https://bugs.launchpad.net/ubuntu/+source/ecryptfs-utils/+bug/1718658

The workaround is to first run

ecryptfs-manager

and then repeat the procedure above.

INFO: Success! Private data mounted at [/tmp/ecryptfs.U15aED2a]

Success!

If you want to browse through the files graphically, run

sudo -i
nautilus

and navigate to the temp directory that was returned. The files are read only, and if you want to copy them somewhere else you will need to run another sudo instance of nautilus.

After you close your root nautilus, don't forget to run

exit

in the terminal to close the root shell too.