Release Notes
for supported DESY Notebooks
with Scientific Linux 4

Updated: November 19, 2005

This is the third release of a supported notebook configuration, after a first year of experience with SuSE 8.2 on the Dell C400 and a second year with SuSE 9.0 on the C400, D600, and X300. It is an attempt to provide easy, failsafe yet flexible handling by the user while keeping support cost low.

Support by - DV - for linux on notebooks is scheduled to end in summer 2006.

This is due to the large amount of work it requires, and the dwindling number of centrally supported devices: It's just too inefficient to spend so much time on a handful of notebooks. Since any other form of support (especially helping with individual problems of users managing their own linux notebook) is even more expensive, our recommendation is to use MS Windows instead.

If you think have a case for the continuation of this support, please let us know.


News and Changes

November 19, 2005 
  • new kernel: 2.6.9-22.0.1.dznb.2
  • added external mouse problem on C400 to known issues
  • added deprecation message
October 17, 2005 
  • fixed a problem with C400 X configuration
  • new kernel: 2.6.9-22.dznb.2
  • fixed update procedure when not on DESY network (alas, still fails to install openafs module for new kernel)
August 20, 2005 
  • The X1 is now supported
August 14, 2005 
August 8, 2005 
August 5, 2005 
  • added X300 information
August 1, 2005 
  • initial release

Older news items are here.

Hardware supported
This setup is available for the DELL Latitude C400, D410, D600, D610, X300, and X1.

The X300 has a broken DSDT that prevents ACPI from working properly unless the patched kernel is used and the DSDT overridden. This is dependent on the BIOS version. The currently supported versions are A04 and A07.

Support for older C-Series models (C6x0, C8x0)could be added, probably with little effort, if development hardware were available.

The Dell D400 has the same DSDT problem as the X300, but no fixed DSDT is available. This model would work, but cannot be recommended for Linux use.

The hardware configuration must be approved by - DV - before purchase, or certain features (in particular, wireless LAN) may not be available.

These features are available on all supported models:

Dual Boot Linux/Windows
Is still supported, but deprecated. Disadvantages include problems with the system clock at least when local time changes from/to daylight saving, increased risk of data loss, reduced security, and higher support cost. Please consider whether your really need windows.

Installations have to be done in the computing center.
Upgrades will preserve the windows installation, /usr1, /home, and the shared storage partition for Windows and Linux (/windows/D) - unless we make a mistake.

Upgrades will not preserve /usr/local.

- DV - provides support for using your notebook for professional purposes only, with an emphasis on mobile use:

We do not support using the notebook as a substitute for your desktop PC or your private PC at home. This includes using external monitors and keyboards, docking stations and printers. Even though much of this is now possible, it's still unsupported.

Using ISDN, DSL and modems should finally work, but is still unsupported. Using an ISDN/DSL to LAN/WLAN router appliance is recommended instead. These are quite affordable today, and allow using the fully supported LAN/WLAN interface of the notebook without additional effort.

Support options are limited to reinstallation if any configuration is modified by means not explicitly approved, or root access was granted.

Please address support requests to and make sure the notebook is accessible via ethernet (not WLAN). Before, please

No phone calls or office visits, except in emergencies, please.

Accounts and access
Our notebooks now know about all AFS accounts enabled in Zeuthen. In addition, there's an account called guest. The list of known accounts can be updated by any user by executing the command nbctl sync. There are no passwords set for any account. Login to any account is possible on the local gdm login screen only, without having to provide a password. Home directories are created automatically during the first login.

Users can arrange for secure, password-less access to their notebook account over the network through ssh public key authentication:

  1. Check whether you possess a file called ~/.ssh/ in your AFS account.
  2. If you don't, create it with the command ssh-keygen -t dsa on any SL3 system. You probably want an empty pass phrase.
  3. On the notebook, make the generated key an authorized key for your account, for example by executing these commands:
    	     kinit            (enter your AFS password)
    	     mkdir ~/.ssh/
    	     cd ~/.ssh
    	     cp /afs/ authorized_keys2
You can now log into your notebook with ssh from your account without password. Don't try this in the opposite direction, it won't work (properly). The file is not secret, hence you needn't worry about sharing the notebook with a colleague afterwards.

The DESY registry should now allow managing passwords for notebook accounts, and this functionality may be added to supported notebooks in the future. But ultimately, securing local accounts on notebooks is impossible without hardware tokens.

The guest home directory is handled specially: It will be removed during every boot process. Up to three instances are kept as /home/guest.1, /home/guest.2, /home/guest.3, and older ones are deleted.

Root access
is not available by default. In fact, the root account has no valid password set, and is only accessible by ssh from our installation server, with the right ssh key. Users do not need access to the root account in order to use the supported set of features, since all approved actions (and even a few deprecated ones) requiring elevated privileges can be performed with nbctl. Run nbctl help and read the output for more info.

On request, a valid root password can be set. Afterwards, we will not provide any support for the device except a complete reinstallation from scratch

The setup should be reasonably secure unless it has been tampered with. Security is however a joke if someone you don't trust has physical access to the device. On the other hand, this fact allows us to keep the account management simple and omit password management altogether.

Each time a network interface is started, an automated check for available updates is performed in the background. If any are found, the user is presented with a pop-up window allowing to either perform all updates, exclude certain packages from being updated, or not to perform any updates at this time. Usually, all updates should be applied as soon as possible. Certain critical packages will have the "exclude" box checked by default although even kernel and glibc updates should work without problems and have been tested successfully. Unless you're at the other end of the world and critically depend on your notebook before you can get to our support again, please uncheck all of them and click ok.

A local firewall is now set up. It should not cause any problems, and obviously should be kept running at all times.

Keeping the notebook up to date
Since an automatic check for updates runs every time a network interface is started, there's nothing to be done but accepting the updates offered.

nbctl sync can be run to trigger this manually.

nbctl yum (or you, for backward compatibility) can be run to only update SL the packages, without running the DESY synchronization (for example, known accounts and software in /opt/products).

Desktop Environments
GNOME is the default and recommended desktop environment.

During your first login, you'll receive a warning that xscreensaver is not available. This is intentional (and the warning is hard to get rid of), so just check the "don't bother me again" box.

To add a battery monitor icon to the panel, right-click the panel, select "Add to Panel", and choose "Battery Charge Monitor". See below for more information about power management.

Locking the screen
Despite the lack of a valid password, it is now possible to lock the screen. For this purpose, a special version of xlock is provided. It will prompt for a password the first time it is invoked. This password is not used for anything but unlocking the screen. Do not use your standard DESY password. The hashed password is stored in the file ~/.xlockrc. If you forgot the password or want to change it, just delete this file.

It is of course still possible for anyone having physical access to your notebook to crash your X server and log in under any account. But your sessions to remote systems will not be accessible.

Software (SL packages)
nbctl software will allow you to install additional SL packages from either our installation server or FNAL. Check the nbctl documentation for details.

Software (DESY packages)
The default installation comes with a fairly complete set of SL3 packages in /opt/products - including cernlib, root, maple, form, and more. The major difference with respect to a desktop system is that usually only a single version is provided due to space limitations. This is not user configurable yet, but will hopefully be eventually. Meanwhile, additional existing packages can be installed on request.

An external USB keyboard should work. If it doesn't, we won't care.

The default layout after installation is U.S. English, and the right Alt key acts as a Compose key:
To enter the character ä, press Alt, then ", then a.

If the system has a german keyboard, and it was forgotten after installation, any user can change the layout to German (latin1 w/ no deadkeys) with the command system-config-keyboard (of course you'll have to type szstem/config/kezboard, though). This GUI application is also available from the GNOME menu ("System settings" -> "Keyboard").

External mouse
You can plug in a USB wheel mouse speaking the MS Intellimouse protocol (these are virtually all mice you're likely to find on the market today) at any time. If this is done before the X-Server is started, it will just work. Otherwise, you can force the running X-server to reinitialize it's list of input devices: Just switch to a text console with, say ctrl-alt-F2 and back with alt-F7.

By default, an external mouse will not disable the touchpad, but see the next item.

The touchpad can be disabled with tp off and enabled again with tp. Check the nbctl documentation for details.

Models with a Synaptics touchpad (sadly, only the X300, X1, C400 and older C-Series) now have an enhanced driver enabling some nifty features:

  • Tapping with two fingers will emulate a click with the middle mouse button. So will tapping in the top right corner.
  • Tapping with three fingers will emulate a right click. So will tapping in the bottom right corner.
  • Sliding along the rightmost edge of the pad emulates a scroll wheel. Scrolling can then be continued by means of circular motions around the pad center.
  • Edge movement (continuation of drag operations when the finger reaches the pad's borders).
  • Many parameters are user-settable. See the file /usr/share/doc/synaptics-0.13.5/README and the synclient man page.

On the X1, single taps are currently recognized as two finger taps. As a workaround, two finger taps have been remapped to left clicks, and three finger taps to middle clicks. For right clicks, the touchpad button must be used. Corner taps do not work as well as they do on the X300 and C400.

Only tapping to emulate a left-click is generally supported on all models.

Using the enhanced driver on models with ALPS touchpad (C840, all D-Series) requires the patched kernel. Even then, it does not work quite as well as a Synaptics pad, and the results are somehwat model specific:

  • Multi finger taps are not available (needs hardware support).
  • On the D600, corner taps tend to produce unwanted multiple clicks and double taps (to emulate left double clicks) are quite sensitive to timing, this needs some practice to get right (tapping with a flat finger is another - possibly easier - way to simulate double clicks).
Users may eventually find settings that work better by experimenting with synclient. Just run synclient -l to see the current settings, and commands like synclient TopEdge=150 to change them.

Storing data
There is a /usr1/scratch directory available, like on any SL3 host in Zeuthen.

There is no backup for any filesystem on the notebook.

Please keep in mind that disks do break, and that they break much sooner if used for tasks a notebook is not designed for, like data taking or large scale data analysis.

Sharing data with windows (on dual boot notebooks)
The windows system partition is not accessible from SL4, due to lack of an NTFS driver, unless a patched kernel is used. Otherwise, it can be mounted (read-only) on /windows/C. Write access is not safe and would almost certainly trash the Windows C: partition.

There's a partition mountable under /windows/D that can be read and written from both operating systems. The drive letter under windows may actually be E or anything else.

Memory sticks
should work. After plugging in the stick, wait for a device icon to appear on the GNOME desktop. It won't happen under KDE where you have to create a desktop icon yourself (do this after attaching).

Don't forget to unmount the device before you unplug the stick, or you will damage the filesystem on it.

LAN (Ethernet)
Is not started automatically during boot.

The interface can be started with the command lan, stopped with the command lan stop, and checked with lan status. Check the nbctl documentation by running nbctl help for details and additional options.

The wired LAN interface is configured for dynamic dhcp by default, but any local user has full control over the device and its configuration. The default configuration can be restored with the command nbctl restore netconfig. This is not an invitation to play with the settings. Only touch the configuration if you absolutely have to.

Wireless LAN
Generally works like LAN.

WLAN is only supported with a Linux compatible device. These include the Dell TrueMobile 1150 (PrismII chip), and the Intel pro Wireless 2100/2200. All notebooks purchased by DESY with Linux in mind have such a card fitted. Notice there are notebooks that were deliberately bought with an incompatible card.

There's a wlan command with the same semantics as lan. In addition to start/stop/status, there are options available for setting the ESSID and WEP key, if necessary, and some more:

  • wlan essid ESSID
    Sets the (extended) SSID if it's not broadcasted. The value is supplied by whoever runs the network you want to use.
  • wlan key KEY
    Sets the WEP key if one is needed to access the network. Again, the value is supplied by whoever runs the network you want to use. Keys may be supplied as ASCII strings, or, more commonly, as hexadecimal numbers. In the latter case, you have to prefix them with 0x (that's zero-x) when feeding them to wlan. Only WEP is supported, more advanced encryption methods like EAP, WPA etc. are not.
  • wlan desy
    Sets KEY and ESSID to the right values for the DESY internal network (for registered and supported/trusted devices).
  • wlan reset
    Sets KEY and ESSID to the default empty values (automatic ESSID detection with no encryption) typical for guest networks.

Check the nbctl documentation for details.

Use afs {start|stop|status}. You can obtain a token with the command kinit. Check the nbctl documentation for details. Remember that your credentials are valid for about 25 hours. If a notebook is passed on to another user within this time, the token may be used to access your files in AFS. To prevent this, use the command kdestroy to delete your Kerberos5 tickets and AFS tokens.

The first start of the AFS client on a newly installed notebook may take a minute or two for the cache initialization. Subsequent starts will be faster.

ISDN, Modem, DSL
nbctl provides support for using and configuring these, and it should no longer interfere with the operation of LAN and WLAN. Check the nbctl documentation for details.

System time
is updated automatically every time you start the network. The source is a DESY timeserver if possible, or on foreign networks. The hardware clock is updated with the current system time during every clean shutdown.

Time is generally a problem on dual boot systems because MS Windows is not capable of calculating the current local time from a system clock set to GMT.

Instead, Windows needs to have the CMOS clock set to local time and will, twice a year, shift it forth or back by an hour. Of course Linux has no chance of knowing whether that already happened.

The only workaround for dual boot systems is: After the change to daylight saving time or back, you must boot Windows first. Automatic drift rate calculation by Linux has been turned off to minimize the effect of failure to do so.

As a very last resort only, run nbctl setclock to start the configuration program for time and timezone. Please make sure you know what you're doing and understand the interaction with windows.

The DESY LPRng printing client software is installed, and the commands /opt/products/bin/lpr etc. precede the SL default ones from cups in the PATH.

By default, all network printers in Zeuthen and most of those in Hamburg are known to LPRng. You may configure additional printers to use in the file ~/.printcap with the following format:

        myprinter| What a nice printer
and then use lpr -Pmyprinter. If a site has no restrictions to using their print servers, you can also use commands like lpr -Psomeprinter@someprintserver.some.domain, without having to configure this printer before.

It is now also possible for a local user to start, stop, and configure the cups printing system and then use commands like lpr.cups. This makes it possible to use locally attached printers. Note that we cannot give any support for things like locally attached inkjet printers.

Work on all supported models. If you run into the problem that a beamer won't adjust correctly to the notebook's signal, try
  • different resolutions (use the Screen Size and Rotate utility from the KDE menu "System Tools" or choose Screen Resolution from GNOME's "Preferences" menu)
  • different screen content (a bright background with sharp contrasts close to the borders often works best)
and rerun the beamer's automatic adjustment. You should (re)start your presentation application after changing the resolution.

There are some model specifics as well:

The Fn-F8 key combo does not work with the current version of the i810 driver. Instead, use the command [nbctl] beamer [{on|off}] which invokes a software switching on and off the VGA output in addition to the LCD panel.
The Fn-F8 key combo allows switching between the LCD panel and the VGA output. To have both active simultaneously, use the command [nbctl] beamer [{on|off}].
D600, D610
The Fn-F8 key combo does not work. The VGA output is always active by default, but can be toggled with the command [nbctl] beamer [{on|off}].The signal is hard to digest at least for some beamers.
With a stock kernel, the Fn-F8 key combo does not work. With the patched kernel, it does work but still should not be used. Instead, use the command [nbctl] beamer [{on|off}].
Use the command [nbctl] beamer [{on|off}]. The native display resolution (1280x768) is not available on the external port. Hence the resolution should be changed to 1024x768 for presentations. This is no loss of functionality, since presentation applications typically only use a 4:3 format anyway. It is recommended to disable display stretching in the BIOS, which makes the X1 very suitable for presentations.

Power Management
The following measures for saving power, especially when running on battery, are in effect:
  • Automatic CPU frequency scaling
  • On models supporting APM (C400 and older C-Series), closing the lid will suspend the notebook to RAM. In this state, a fully charged battery will last for about two days (and then the notebook crashes unless it resumed and shutdown cleanly before).
  • On all other models, closing the lid will turn off the display backlight.
  • On models supporting it (all except the D410), xlock will turn off the display backlight (except during the first time when the password is set). These models allow turning off the backlight anytime with the command xset dpms force off.
  • When running on battery,
    • the services crond, atd, and anacron are stopped.
      This prevents CPU/disk-intensive background tasks from being performed, like prelinking, or updating the whatis and locate databases. The services are restarted as soon as an AC adapter is plugged in.
    • laptop mode is turned on.
      This will tune the virtual memory subsystem to minimize disk accesses: Readahead is increased, and write accesses will be clustered as much as possible.

      For up to ten minutes, changes will NOT be written to disk, but kept in memory only. You can however force this by executing the command sync anytime you like.

      In addition, the hard disk spindown timeout is set to a very short time, and the internal hard disk power management is set to "aggressive", if possible (models with PATA drive only, until support for this is added to the SATA driver in the kernel).

      All eligible filesystems are remounted with the "noatime" option, disabling access time updates, because access time updates - which happen for every read access - are writes.

      To make these measures effective, also the syslog configuration is generally modified to prevent syncing after every logged message.

    These measures are not available on the X300 if a stock kernel is running, due to broken ACPI tables (no battery/AC adapter events). Hard disk power management is not available on the D610 yet (SATA disk).

What users can do to save battery power:

  • Turn down the display brightness (Fn-downarrow).
  • Turn off the backlight as described above.
  • Stop the LAN/WLAN if you don't need it.
  • Turn off the WLAN antenna (Fn-F2) on D-Series models if you don't need it.
  • Remove unnecessary PCMCIA cards.
  • Don't waste CPU on fancy screensavers.

With these measures in place, all our "normal" notebooks should work on battery for more than four hours (at low display brightness and CPU usage). The extremely small and light models X300 and X1 should still exceed 2.5 hours.

General known issues
  • Updates, including kernel updates, now work from anywhere. However, the mechanism that installs the openafs kernel module still only works when on the DESY internal network.

    It is possible to install the matching kernel-module-openafs-`uname -r` package manually with yumex (nbctl software) though. Missing openafs kernel modules are installed automatically when the notebook is synced in the internal network the next time.

Dell C400 known issues
  • Pressing the power button will immediately turn off the notebook, without performing a clean shutdown. Don't do this.
  • Suspending in general works well, but if the notebook is suspended while the fans are running, they sometimes will never stop after a resume, so you probably want to wait for the fans to stop before suspending. There's a rumor that the key combination Fn-Z (on a german keyboard, that's Fn-Y) will make the notebook re-read the sensor data which should cure this. Feedback whether it really helps is welcome.
  • An external USB mouse currently does not work as advertised. This is because the touchpad and joystick are handled as two mice by the driver. The script modifying the X configuration has to be adapted to this, which is not quite simple (especially without development hardware) but will be done eventually.
Dell D410 known issues
  • Suspending the notebook is not possible (to be exact, suspend to RAM works, but resume does not ;-)
  • xset dpms force off doesn't work
  • Closing the lid will reliably turn off the backlight, but a hack needed to be scripted to turn it on again when the lid is opened. This may take a few seconds and an additional keypress.
Dell D600 known issues
  • Suspending the notebook is not possible
  • The VGA signal is hard to digest for at least some beamers. See above for hints how to deal with this.
Dell D610 known issues
  • Suspending the notebook is not possible
  • The VGA signal is hard to digest for at least some beamers. See above for hints how to deal with this.
  • Since this model comes with an SATA drive, hard disk power management is stuck with whatever is set by the BIOS. The RH kernel does not yet support changing these settings.
Dell X300 known issues
  • Suspending the notebook is not possible
  • This model has a broken DSDT (ACPI tables). This makes it impossible for Linux to recognize the battery and AC adapter status. In addition, the key combinations to change the display brightness does not work. There is a fixed DSDT available to cure these problems (and then, the X300 is a very nice Linux notebook), but the RH kernel lacks the patch needed for overriding the DSDT. Hence this requires the patched kernel.
  • With the stock kernel, the key combination for (de-)activating the WLAN antenna does not work.
Dell X1 known issues
  • Suspending the notebook is not possible
  • xset dpms force off doesn't work
  • Closing the lid will reliably turn off the backlight, but a hack needed to be scripted to turn it on again when the lid is opened. This may take a few seconds and an additional keypress.
  • The CompactFlash and SecureDigital/MMC card readers have not been tested. They may or may not work.
Known issues after upgrade from SuSE 8.2
  • This is completely untested, and anything may happen. The 8.2 setup has been unsupported for more than a year, and we recommend a reinstallation from scratch (wiping out everything except the windows system partition) rather than an upgrade.
Known issues after upgrade from SuSE 9.0
  • Many dot-files in existing homedirectories have to be renamed to ...disabled_by_SL4install or ...saved_by_SL4install since their SuSE-specific content does not work properly under SL.
Known issues after reinstallation of SL4
  • Some dot-files that may exist on bot SuSE 9.0 and SL4 in existing homedirectories have to be renamed to ...saved_by_SL4install for the reason given above.
Missing features
Bluetooth is not yet supported. Nor is Firewire (it is not supported by RHEL4). The email transport is not configured, and it is highly recommended to ssh into a DESY system and send mail from there and not from the notebook. A VPN client is not provided. Suspend to RAM should be implemented as soon as the necessary kernel support is available from the stock SL kernel.
Unsupported features
We do not and do not plan to support using the internal softmodem, Infrared port, PCMCIA storage devices, docking stations and using the external VGA port in any mode except "clone".


Ethernet (LAN) does not work
  • make sure only one interface is up at all times - run lan to stop all interfaces and start eth0
  • make sure it is configured properly - use nbctl restore netconfig if in doubt, then restart it

WLAN does not work
  • Is the antenna turned on? (D-Series, #1 mistake, really)
    Unfortunately, this can be tedious to find out: If pressing Fn-F2 turns on the Bluetooth LED (yes, the blue one), that's the setting you want. However, some Notebooks were purchased without Bluetooth although this is the agreed standard setup, it's cheap and this cannot be retrofitted. On systems with Intel Pro Wireless 2100/2200 chips, nbctl will detect that the antenna is disabled and print a warning when attempting to start the interface. Let's hope all the others have the bluetooth module. The antenna cannot be disabled on C-Series notebooks, except in the BIOS.
  • Are the ESSID and WEP key set to the right values? - Run wlan reset or wlan desy or whatever is appropriate, then restart; reboot if desperate (the WLAN chip sometimes gets hooked on the wrong ESSID in environments where more than one of them works)
  • Check all items given for LAN above.

Time is off by one hour or keeps getting messed up
  1. if this is a dual boot system, boot windows and then shut down
  2. boot Linux, then start a network interface, or run nbctl setclock
  3. check the system time with the date command
  4. shut down cleanly

I (my colleague) cannot log in
Accounts must be enabled for DESY Zeuthen or they won't work on the notebook. If this is true for the account in question, the notebook probably doesn't know yet:

  1. log in (use the guest account if necessary)
  2. attach the notebook to the DESY LAN (or WLAN, ISDN dialup also works)
  3. run nbctl sync, unless this part has already been run during automatic updating after starting the network interface

Patched Kernels for Notebooks

Since some important functionality is not available with the stock SL kernel, a kernel modified for notebook use has been built at DESY Zeuthen. It can be recognized by the string "dznb" in the release (output of uname -r) and provides In the future, support for suspend to disk may be added.

Using such a patched kernel has the disadvantage that it will have to be recreated with every kernel update. This may be impossible to do timely, or with all features (previous patches will not necessarily work with the latest kernel release). In addition, such kernels will only be available from the Zeuthen repository.

Installing and using the stock kernel will not break the notebook since the additional features are all autodetected, but functionality will be reduced. On the other hand, even after a new vanilla kernel was installed, the old enhanced one will still be available to boot by simply choosing from the boot screen. However, kernel updates are usually due to security reasons, and users are advised to use the latest kernel at least when the notebook is attached to any network. A new release of the enhanced notebook kernel will then be offered as an update as soon as it has been built.

Stephan Wiesand