login returns to login screen

Which version of Ubuntu?

I'm using 10.04.3, having applied all updates since initial install of 10.04 Linux Format cover disk.

At the moment I am in the middle of running fsck from sysrescue disk, although it has been on 87.43% for the last hour.

So, I think I may have a problem with my hard disk, despite the fact that a non-full fsck and the default check in sysrescue says the disk is clean.

When I try to backup files onto a pen drive (at the command line), something like 50% of the files claim to have an I/O error and won't write. (It bothers me it's 50% of them. Why not all, or none, if the disk controller is, or isn't broken? Surely I cannot suddenly have that many bad blocks appear?)

Anyway if you can point me to a "fix X" option in safe boot, that would be great, I'd still like to try that - although part of me thinks the loop-back-to-login error indicates something much worse than just the loss of a config file ...

(Oh by the way, I don't think the problem is monitor or graphics chips, I can run sysrescue in graphical mode without apparent problem.)

I had a similar problem with login returning me to the login screen. I've been at this for a week and finally figured out how to fix my machine. Try this:

1. Attempt a login using the usual login panel.
2. Reboot and enter recovery mode.
3. Choose the option to continue to reboot normally -- and get to the recovery mode console. Login as yourself.
4. Cat the file $HOME/.xession-errors

The files in /var/log/gdm/ also contain logging from gdm, your display manager.

There is an old entry from a user who had a similar problem years ago -- their problem was that permissions for /tmp had been changed on upgrade. My system's permissions were fine, but you should check this, too.

Thanks Jacobsallan for the advice. Now I have got as far as finding the
Xsession error 'can't find /home/simon/.profile', although that file
DOES exist (and is readable after console login) and just for good
measure I tried again after giving it 666 permissions... no difference.

It looks like maybe the filesystem isn't mounted, but in that case I
would surely never have reached Xsession... so I am really baffled. But
I will investigate further when I find time!

On Mon, 2011-09-12 at 04:25 +0000, Jacobsallan wrote:
> Your question #170756 on gdm in Ubuntu changed:
> https://answers.launchpad.net/ubuntu/+source/gdm/+question/170756
>
> Jacobsallan posted a new comment:
> I had a similar problem with login returning me to the login screen.
> I've been at this for a week and finally figured out how to fix my
> machine. Try this:
>
> 1. Attempt a login using the usual login panel.
> 2. Reboot and enter recovery mode.
> 3. Choose the option to continue to reboot normally -- and get to the recovery mode console. Login as yourself.
> 4. Cat the file $HOME/.xession-errors
>
> The files in /var/log/gdm/ also contain logging from gdm, your display
> manager.
>
> There is an old entry from a user who had a similar problem years ago --
> their problem was that permissions for /tmp had been changed on upgrade.
> My system's permissions were fine, but you should check this, too.
>

Yep, that fixes it - thanks a million - certainly 1000x better than a distro re-install, which I was close to. So far, the rest of my system seems to be completely untouched/as was - perfect solution!

(Well, not quite as good as not going wrong in the first place, but you know what I mean :-)