How To Get Ltsp5 Working On Opensuse

I'm posting also so that I have the notes when I forget what I've done.

LTSP (ltsp.org) is a big package for serving thin clients. See the site for further explanation.

LTSP5 differs from earlier LTSPs in that the client starts a session from LDM logging via ssh -X to the server instead of connecting to a GDM, KDM or XDM session. Currently the package only caters for Ubuntu but it's not hard to get working on other distros. I'll just mention the differences that need to be overcome, you'll have to read up on the basics of thin client booting and admin, its a very long story, too long for here.

Get the Ubuntu LTSP5 .bz2 tarball from ltsp.org.

Unpack in /opt.

Copy the stuff in /opt/ltsp/ubuntu_6.10_i386/boot/ to a subdirectory of $TFTPHOME (usually /srv/tftpboot or /tftpboot), say lts/2.6.17-10/.

The DHCP entry for the thin client should have:

filename "lts/2.6.17-10/pxelinux.0";
option root-path "/opt/ltsp/ubuntu_6.10_i386";

inside the {}s, or be the defaults for all thin clients if all your clients are the same.

Restart dhcpd if you've edited the config file.

Make sure tftpd is running (usually under xinetd).

Make sure the NFS server is running and that this path is exported by the NFS server:

/opt/ltsp/ubuntu_6.10_i386 *(rw,no_root_squash,sync,no_subtree_check)

(or your subnet/mask instead of *)

I think it can be ro, but I'm not sure. Run exportfs -a if you've edited /etc/exports.

First problem is that ldm calls ssh -X to run /etc/X11/Xsession at the server end. On OpenSUSE, Xsession is at /etc/X11/xdm/Xsession, so edit /opt/ltsp/ubuntu_6.10_i386/etc/lts.conf and add:

LDM_REMOTECMD=/etc/X11/xdm/Xsession

Second problem is that the client requires the host keys because it's paranoid. On Ubuntu one would run a utility program to grab the host keys. On OpenSUSE you have to do it manually. In /opt/ltsp/ubuntu_6.10_i386/etc/ssh/ssh_known_hosts, put the public keys of the the server, from /etc/ssh/ssh_host*_key.pub. I think it wants the DSA key but I put in all three, RSA, DSA and DSS. Note that the lines need a slight edit to put the domain name,ip address at the beginning of each line and the user@host is not needed. See $HOME/.ssh/known_hosts if you want a reminder of the format.

Assuming your thin client has a PXE NIC, on boot it should get an address and load the kernel and initrd. You will see the Ubuntu splash screen then the ldm screen. You should then be able to login with a server account and password, and be amused to get an OpenSUSE desktop.

Things to check: DHCP server running, TFTP server running, ssh allowed into server, NFS exports allowed out of server.

I'm still not decided if I like LTSP5. It requires a ssh session meaning all X traffic goes through this encryption even if you have your own LAN so it may not be so good for low MHz clients. On the other hand the security of the approach is indubitable.

Best place to get help is the LTSP or Ubuntu-LTSP forums. There is hardly anything that is OpenSUSE specific.

Addendum: the old less secure but less CPU intensive xdm method can be enabled, see

http://doc.ubuntu.com/edubuntu/handb...sp-client.html

I should also add that OpenSUSE has a similar system called kiwi-ltsp. Same principle: a directory tree is populated from distro specific packages that are needed by the thin client, rather than using LTSP4 packages, then this directory tree is exported to be the root filesystem of the thin clients.

Kiwi-ltsp gets its packages from a 10.3 i386 installation source (e.g. DVD), and the result is something the thin client can network boot and mount.

Documentation is at opensuse.org, search for LTSP. There are still several bugs, see the bug reports in bugzilla. It's early days yet, I managed to file bug #4. But it works quite well and is an alternative to seeing the *buntu spash screen on login, instead you get the green 10.3 splash screen.

This is a valuable thread ken-yap.. Thanks!

I will be giving this a go next year

This is actually also relevant to LTSP4. I have always wanted to direct sound to my thin client instead of to the server's audio output. LTSP can run an esound daemon on the client and you can set ESPEAKER like DISPLAY, e.g. export ESPEAKER=terminal.example.com:16001 and savvy apps can send the sound there. The one I wanted most was Flash. Now it seems that Adobe supports various sound systems using libflashsupport.so in Flash9. You can get the details at http://www.pulseaudio.org/wiki/PerfectSetup abd http://pulseaudio.revolutionlinux.com/PulseAudio which show you what you need to do.

Because I run x86_64, compiling the 32-bit library from source was problematic, so I cheated and installed the Mandriva RPM, ignoring the libssl-0.9.7 dependency. Well it turned out that I should not have just swept this one under the carpet. After some debugging by

FLASH_PULSEDEBUG=1 firefox

I found that the step that made it work was

ln -s /usr/lib/libssl-0.9.8.so /usr/lib/libssl-0.9.7.so

Now I can hear youtube videos at my terminal.

Really, Mandriva ought to get up to date with libssl.

I should also add that OpenSUSE has a similar system called kiwi-ltsp. Same principle: a directory tree is populated from distro specific packages that are needed by the thin client, rather than using LTSP4 packages, then this directory tree is exported to be the root filesystem of the thin clients.

Kiwi-ltsp gets its packages from a 10.3 i386 installation source (e.g. DVD), and the result is something the thin client can network boot and mount.

Documentation is at opensuse.org, search for LTSP. There are still several bugs, see the bug reports in bugzilla. It's early days yet, I managed to file bug #4. But it works quite well and is an alternative to seeing the *buntu spash screen on login, instead you get the green 10.3 splash screen.
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I followed the instructions on the kiwi list site,

http://lists.berlios.de/pipermail/kiwi-devel/2008-January/000287.html

to install kiwi-ltsp but it keeps failing. I modified the kiwi-ltsp file to reflect the information but when I run kiwi-ltsp-setup -s as root it fails. I keep getting No subnet declaration for eth0 (my server ip address). Not configured to listen on any interfaces!

Any idea on what I could be doing wrong?

That's from the DHCP server. What did you set the DHCP_ variables in /etc/sysconfig/kiwi-ltsp to?