UbuntuHelp:UbuntuLTSP/ClientTroubleshooting

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https://help.ubuntu.com/community/UbuntuLTSP/ClientTroubleshooting

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This page is specific to Ubuntu versions 8.04, 8.10, 9.04, 9.10, 10.04

If you find this information applicable to additional versions/releases, please edit this page and modify this header to reflect that. Please also include any necessary modifications for this information to apply to the additional versions.

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Sometimes you need to troubleshoot the thin client boot process. This is fairly easy if you understand the concepts behind LTSP and the boot process of a thin-client.

Troubleshooting at the client itself

• First, let's temporarily disable the Ubuntu bootsplash for the chroot environment, so we can see bootup messages scroll by:

sudo vim /var/lib/tftpboot/ltsp/i386/pxelinux.cfg/default

Remove the word quiet and splash. Save and exit, and reboot the thin-client. You should now see all bootup messages instead of the Ubuntu graphical bootsplash.

• In the case of X not launching, and nothing valuable in dmesg, you want to be able to log into the chroot environment to examine the logs contained in /var/log (you can't do this on the server as /var/log on the client is stored in RAM). Let's activate|the root account in the chroot. To create an administrative user account in the chroot that can sudo to root, see create|an admin account in the chroot.
• ...and now we reboot the thin client, log into the chroot to examine the logs:

~-(On the thin-client)-~

• CTRL+ALT+F1 will get you to a TTY to log in, even if X is giving you a blank screen.
• Log in with your newly unlocked root account, navigate to /var/log, and check out Xorg.6.log (amongst others that might pertain to your situation).

Using a shell SCREEN

Instead of unlocking the root account and updating the image, there's a quicker way to get local root access to an LTSP client. Open or create the lts.conf settings file, by running

sudo gedit /var/lib/tftpboot/ltsp/i386/lts.conf

Then, paste the following into it:

[Default]
SCREEN_02=shell
SCREEN_07=ldm

As soon as the client is rebooted you'll be able to press Ctrl+Alt+F2 to get to a local root prompt, while Ctrl+Alt+F7 will get you back to the LDM display manager.

Troubleshooting via SSH

Shamelessly ripped off from https://help.ubuntu.com/community/HowToSetupLTSPDevelEnvironment It's really useful to be able to start a shell on a thin-client when debugging or development. Let's install openssh-server into the chroot,

• SSH needs /dev/random and proc interface, so mount them:

sudo mount --bind /dev /opt/ltsp/i386/dev
sudo mount -t proc none /opt/ltsp/i386/proc

• Now, install the SSH server in the chroot, telling the server not to handle the start/stop of the daemon (since we're working in the client filesystem):

LTSP_HANDLE_DAEMONS=false
sudo chroot /opt/ltsp/i386 apt-get install openssh-server

• If you want to unlock the root account and set a password:

See activate|the root account in the chroot.

• To create an administrative user account in the chroot that can sudo to root:

See create|an admin account in the chroot

• Lastly, rebuild the client image:

sudo ltsp-update-image

Reboot your thin clients, and you should have a functioning client-side SSH server!

Using remote syslog facilities

• Alternatively, you can Enable|thin-client syslogging to the LTSP/syslog server.