really, really locked out, can't change password

[linbo]

I've searched and searched and cannot find the solution to my locked out problem

I was using Ubuntu on my home computer three years ago for remote work and have not tried to log in since then. Now I'd really like to login again.

I boot my computer using the last recovery kernel available (it's ubuntu 10.something but I don't think the version is really the problem)
I select the boot to root shell then try to reset my password
I get an error message:
"Authentication token manipulation error"

I try all the various fixes in all the searches, i.e.
I check write permission for / and /etc both are rw for root
I still try the mount command, >> mount -o rw,remount /
but that produces an error saying I cannot remount

OK so I check write permissions for /etc/passwd and /etc/shadow, both are rw for root. Both files have an entry for acorn user and the shadow file has a long encrypted string in the password field (second from username)

What can I do?
I've read all sorts of posts about copying the shadow file, using some utility to delete the shadow file, logging in using ssh, etc.
None of these solutions seems right. I don't have a backup and so I'm hesitant to just go in and muck with these files. Not sure if I can copy all the Ubuntu stuff from Windows side (I have a terabyte standalone drive so space isn't an issue)
Right now I'm posting this from the Windows side.

Does anyone have any suggestions?

[Toz]

I boot my computer using the last recovery kernel available (it's ubuntu 10.something but I don't think the version is really the problem)
I select the boot to root shell then try to reset my password
I get an error message:
"Authentication token manipulation error"

Its probably because the filesystem is mounted readonly. Remount it as read/write then try resetting the password again:

mount -rw -o remount /

[linbo]

Um, I've tried that. Not sure why my post isn't showing. I've checked all the rw permissions, /, /etc, /etc/shadow, /etc/passwd, and tried remounting. All permissions show rw in the root field (i.e. first area) and remount gives error message

thanks

[Toz]

..... and remount gives error message

What is the error message?

What does the following command show?

mount

[Iowan]

Have you tried creating another user? The new one wouldn't have sudo privileges, but would be a step forward.

[linbo]

Hmm, haven't tried creating a new user--is there a way to do this while still in the root recovery shell? Meaning I have no access to the regular commands or apps

[Iowan]

adduser would be the command - man adduser for details.
(I always get confused between adduser and useradd)

[linbo]

mount -o rw,remount /
gives error message:

......EST4-fs error (device loop0): ext4_remount: Abort forced by user.........
......mount: cannot remount block device /host/ubuntu/disks/.............
......riit,dusj read-write, is write-protected

the ...... are where the text runs off the screen, i.e. I cannot see the entire error message

the mount command by itself gives a page of lines, too many to write down--no errors but a warning at the bottom
warning /etc/mtab is not writable e,g, read-only file system

I hesitate to change permissions on this without knowing what I'm doing.

I'll try creating a new user next

[carboi82]

http://www.howtogeek.com/howto/linux...nutes-or-less/ The second half of that how-to has worked for me in the past...

[linbo]

no success

adduser yields error message:
>adding user lingo
>adding new group linbo
>groupadd: cannot lock /etc/group; try again later
>adduser: '/usr/sbin/groupadd -g 1001 linbo' returned error code 10 Exiting

useradd yields error message:
>cannot lock /etc/passwd

second methd from howtogeek yields
"Authentication token manipulation error" message when I get to the point of changing the password for acorn user

It's clear that this is a write permission problem. Should I try a different title in hopes of snagging an expert that knows how to force the write permissions?