Xsession warning: can't login, can't find solution

[danuntu]

I currently have two computers running kubuntu 10.04. one has been running for 2 or 3 years - no problems, always updated, even upgraded to each new distro - no problem. the other is a fresh install - all updates applied, everything's great, right?

Ok, the problem. Now, both computers, after rebooting, give the following error after login:
Xsession: warning: unable to write to /tmp: X session may exit with an error
....with a button that says "okay".

Usually, i have no problem searching for a solution for errors such as this. However, everything I have found thus far has suggested

sudo apt-get clean

. For most people that used this it fixed their problem. apparently, they issues with hard drive space. Ok, even my older box only has 46% used after running

df

. and the newer box is only at 6%.

Can someone please help. I greatly depend on my only computer.
Your help is appreciated.

[oshunluvr]

Re: Xsession warning: can't login, can't find solution

I'd start with looking at the permissions of /tmp and anything in it. If you have a separated mounted partition as /tmp - umount it and try to start X. If you have /tmp as a subdirectory of your root partition, try renaming it and creating a new empty /tmp and setting permissions to +rwx. You may have to do this from a livecd boot.

It's very suspicious that both computers have this error simultaneously - likely your last update broke something or maybe you launched a GUI program as root

[danuntu]

Re: Xsession warning: can't login, can't find solution

Understood, i did install virtualbox on the new install, but don't remember running it as root. But possible. the /tmp dir is a subdir. I would like to create a seperate partition, but i'm a little unsure of the process.

Thank you for such prompt response.

[oshunluvr]

Re: Xsession warning: can't login, can't find solution

I'm pretty sure you can't do this while logged in. I'm also unsure where your error is occurring - does kdm (the log in screen) start ok and the error happens when trying to log in?

Assuming this is the case, do a CRTL-ALT-F1 to get to a text console, log in and kill X (sudo service kdm stop), then do these:

sudo mv /tmp /tmpold
sudo mkdir /tmp
sudo chmod +rwx /tmp
sudo service kdm start

In theory: this should start you with a new clean /tmp. If this allows you to go back to work - then problem solved. If not - post your error messages in as much detail as you can.

Also - if you get an error trying to rename /tmp above - you may have to boot to a livecd or usb, let me know

[danuntu]

Re: Xsession warning: can't login, can't find solution

osh, on the new install i entered your instructions just as you said. i got no errors from any command. the login screen runs fine, as it did before. this time, instead of going to the desktop, it just goes right back to the login screen. so i tried logging in again. the screen turns black as if the monitor powers down. again, no errors. is there a log file that may be catching anything by default? or should i go ahead and try again from a livecd

I will post again after trying this on my old computer.

Thanks again and sorry for the delay getting back. gotta work sometime.

[danuntu]

Re: Xsession warning: can't login, can't find solution

one more note on the same computer. before running your commands, i could cd to /tmp and list the contents. now i get permission denied on that directory. however, i'm not getting the xsession warning error. i assume that means my user doesn't have permission now but root does. do i somehow need to change the permissions on mine again?

[danuntu]

Re: Xsession warning: can't login, can't find solution

ok, the older computer is the same as the other one now. it's like only root has access to the /tmp directory. surely my free space of 49% on the hd isn't effecting this?

[Snowhog]

Re: Xsession warning: can't login, can't find solution

This is begining to sound a lot like you've been launching graphical applications from the command line (console) using sudo app_name (Dolphin ?) and then opperating within your home partition and making changes. Is this the case?

[danuntu]

Re: Xsession warning: can't login, can't find solution

i think that did happen on both computers, but i didn't know that wasn't good. if so then what do i do? my older installation is where i have family vids,pics,etc...

[oshunluvr]

Re: Xsession warning: can't login, can't find solution

Usually the circular login is caused by a critical file in your user directory being owned by root.

On that computer: log in at the text prompt again like before.

Substitute your username and group for USERNAME and GROUP in the commands below:

sudo chown USERNAME:GROUP /home/USERNAME
sudo chown -R --preserve-root USERNAME:GROUP /home/USERNAME/*

this should fix it.