5   Configuration of the X Window servers

5.1 Display connection
5.2 Screen arrangement
5.3 Backing Store
5.4 Hewlett-Packard HP-UX X Window server
5.5 Hewlett-Packard Tru64 UNIX X Window server
5.6 IBM AIX X Window server
5.7 Sun Solaris X Window Server
5.8 Xi Graphics Accelerated-X X Window server

Since X-META-X does not substitute, but cooperates with the X Window servers, the servers themselves need appropriate configuration, too.

Here some general rules are followed by hints for particular X Window servers. The sections about the individual options and about authorization (6.8 Authorization) contain further information on the configuration of the X Window servers.

5.1   Display connection

Usually the X Window clients connect themselves to the display connection :0 of the X-META-X proxy. Because two servers cannot share a common communication port, the (local) X Window server must be configured with a different display number, for instance :1. Normally this is the first argument of the X Window server command.

5.2   Screen arrangement

Most X Window servers provide for more or less flexible configuration of the controlled screens. Since every X Window server controls the screens totally independently - therefore X-META-X - this configuration mainly affects the way how to control multiple screens with one mouse only.

The arrangement of the screens determines on which screen the pointer image reappears after crossing a screen border. Because X-META-X allows strange, irregular screen arrangement, the X-META-X proxy controls the mouse pointer totally independently. Therefore, the controlled X Window servers should be configured so that the pointer cannot be moved off a screen. If this is impossible, the servers should be configured as if the screens were arranged in a horizontal row.

5.3   Backing Store

If the configuration contains many screens displaying distinct areas of a meta screen, the X Window servers should not allow backing store. This may be achieved by the -bs X server argument. Without backing store, the X-META-X proxy is able to further optimize drawing operations with respect to speed (6.12.9 Screen tags).

Backing store support affects the playback of a recording, too. Fullscreen playback (11.3.14.3 Scope and sort of the playback) as well as directly copying (11.3.15 Direct copy) is carried out more efficiently, if backing store was or is disabled during recording.

5.4   Hewlett-Packard HP-UX X Window server

If the X Window server is started with a display number which is different to the default value :0, the configuration files /etc/X11/Xdisplay_number* should be created by copying the corresponding X0* files, for instance for the display name :1:

cd /etc/X11
cp X0devices X1devices
cp X0pointerkeys X1pointerkeys
cp X0screens X1screens 

In the configuration file /etc/X11/Xdisplay_numberpointerkeys one specifies the screen arrangement. The special mouse handling by the X Window server should be switched off:

screen_change_amt    255
screen_row_wrap      nowrap
screen_col_wrap      nowrap 

If you experience jerky pointer movements on remote servers, the pointer statement (6.12.6 Mouse pointer) might help.

5.5   Hewlett-Packard Tru64 UNIX X Window server

The X Window server gets the arrangement of multiple screens through the -edge_* command line arguments. The special screen number -1 totally disables pointer traversal (here for a two screen configuration):

/usr/bin/X11/X -edge_left0 -1 -edge_right0 -1 \
    -edge_left1 -1 -edge_right1 -1 

However, certain versions of the Hewlett-Packard Tru64 X Window Server show several bugs with such a configuration. You should not use the -edge_* command line options in those cases.

There is an easy workaround for an other server bug: if the pointer cannot be moved to the last pixel row at the right and bottom edges, the width of the borders must be enlarged to at least two pixels using one or both of the following sub-statements (6.12.4 Dimensions of a screen):

    displayWidth -2
    displayHeight -2 

followed by (6.12.5 Border width of a screen)

    borderWidth 2 

Some clients of the DECWindows environment use certain enhancements of the Hewlett-Packard Tru64 X Window server only if they recognize the server by the vendor string. The configuration statements

vendorString same
vendorReleaseNumber same 

let the X-META-X proxy pass on the (first) server's name and release number unmodified (6.15 Miscellaneous statements).

Some versions of the Hewlett-Packard Tru64 X Window server yield wrong pointer coordinates in certain situations. The configuration statement

workarounds fixPointerCoordinates 

fixes this bug (6.13.1 Faulty pointer coordinates).

For improving the interactive performance the xmetax program (6.15 Miscellaneous statements) as well as the X Window (6.7 X Window server) server should be executed with raised priority.

5.6   IBM AIX X Window server

The X Window server gets the arrangement of multiple screens through the -P* command line arguments. In order to avoid that the server moves the pointer from screen to screen, the screens should be configured diagonally, like in:

/usr/lpp/X11/bin/X :1 -force -P11 iga0 -P22 bl0 -P33 bl1 

The lsdisp command shows you the names of the graphic devices.

In the case of a heterogeneous DYNAMICSERVER configuration (9 X-META-X Option DYNAMICSERVER) or with the VARIO option (7 X-META-X Option VARIO) the X Window server shows two peculiarities regarding fonts:

• The default font is Ergo15.iso1 instead of the usual fixed. The arguments -fn fixed let the X Window server load this font. Alternatively you may let the X-META-X proxy know the special font by using the statement fontName Ergo15.iso1 (6.15 Miscellaneous statements).
• However, the fixed font like many others is stored in the directory /usr/lib/X11/fonts/ instead of the misc/ subdirectory. Thus, there is no uniform architecture-independent font path. This problem can be solved by a font server.

5.7   Sun Solaris X Window Server

If the X Window server is started with a display number which is different to the default value :0, it may display non-fatal warning messages during server initialization. They are eliminated by adding the appropriate display specification to the server configuration file /etc/openwin/server/etc/OWconfig. If this file does not exist, then copy it:

mkdir -p /etc/openwin/server/etc
chmod a+rx /etc/openwin/server/etc
cp /usr/openwin/server/etc/OWconfig \
    /etc/openwin/server/etc/OWconfig 

Copy the specification of the resource of class XDISPLAY and name 0, then only change the name to the appropriate display number, here :1:

class="XDISPLAY" name="0"
    coreKeyboard="IKBD" corePointer="IMOUSE"
    dev0="/dev/fb";
class="XDISPLAY" name="1"
    coreKeyboard="IKBD" corePointer="IMOUSE"
    dev0="/dev/fb"; 

If a screen is to be rotated by the VARIO option (7 X-META-X Option VARIO) the X-META-X proxy uses a virtual input device for direct control of the pointer image. With newer X Window servers this device is already configured. If you experience jerky pointer movements, add the following lines to the configuration file /etc/openwin/server/etc/OWconfig:

# Virtual mouse for X-META-X/VARIO
class="XINPUT" name="VIRTUALMOUSE"
    ddxHandler="ddxSUNWmouse.so.1"
    ddxInitFunc="ddxSUNWmouseProc"; 

In rare case you will need the absoluteInputDeviceMode workaround (7.2.2.1 Faulty pointer coordinates mode):

workarounds absoluteInputDeviceMode 

5.8   Xi Graphics Accelerated-X X Window server

If a screen is to be rotated by the VARIO option (7 X-META-X Option VARIO) the X-META-X proxy tries to use a virtual input device for direct control of the pointer image. To configure this device run Xsetup in graphical mode from within an X11 session and register a new virtual mouse pointer input device called NULL Mouse with three buttons, x/y axes and mode different than POINTER. Afterwards, restart the X Window server to make the changes effective. If this does not help, try other combinations of device parameters.