4

Supporting a Centralized System - IBM

This chapter contains procedures for setting up the necessary operating system support files. Use the Workbook in Chapter 2 to determine the procedures needed.

The values selected in the remote configuration file dictate the operating system files that must be enabled, created, or modified.

• NFS directories must be exported if NFS is used for booting or file access.
• tftp must be configured and enabled if tftp is used for booting or file access.
• bootp must be configured and running for the network computer to automatically find boot information for a tftp or NFS boot.
• xdm must be configured and running if host connection method is xdmcp.
• If Domain Name Service (DNS) is used, the network computer entries must be added to the zone and local host files.
• Several Local Clients are available and can be started with xpsh or the Client Launcher (See Chapter 9, Local Clients).
• Local Motif Window Manager (MWM). (See Chapter 10, Window Managers).

Note:

You must log in as root to perform the tasks in this chapter.

Enabling NFS Access

This section describes the steps necessary to set up the NFS host so the network computer can search the host for fonts and configuration files. You need to enable access if the primary or secondary file access method or the boot method is set to NFS.

If you have the SMIT interface, use the following menu path to access NFS information. In addition, export entries with the read-mostly option.

Communication Applications and Services -->
NFS -->
Network File System (NFS) -->
Configure NFS on This System -->
Start NFS

Respond to the following by accepting both, the system default.

Start NFS now, on system restart or both   both

Press Enter or, if using the window interface, click DO.

Follow any additional instructions provided by the Command Status screen. When the status is displayed as OK, the command is complete.

Use this procedure if you do not use SMIT:

1. Edit the /etc/exports file. Add each of the file systems to be exported at boot time, along with any options.

   The file systems must be exported to be accessible to the network computer. The exported systems are specified with an nfs_table command in the xp.cnf file, or in the nfs.tbl file. An example xp.cnf file entry:

   nfs_table "montana:/tekxp" "/tekxp"  "8192"

   An example nfs.tbl entry:

   montana:/tekxp /tekxp 8192

   /etc/exports entry, shown with the read only option (-ro):

   /tekxp -ro

2. To enable the mount point immediately, without booting, run:

   # /usr/etc/exportfs -a[-o options]

3. Use /usr/etc/exportfs without any parameters to verify the exports.
4. Edit the /etc/hosts file and add the network computer name and address. For example:

   128.07.60.30 portland
   128.07.60.31 corvallis

5. Update the arp table to add the new entries:

   # arp -s ether portland 08:00:11:01:00:45
   # arp -s ether corvallis 08:00:11:01:00:46

   The ether switch indicates you are providing an hardware address. If you are installing a large quantity of network computers, you might want to take advantage of the -f filename option to the arp command. Where filename is a file of all the network computer entries to set.

6. Use the ps command to see if nfsd is running:

   # ps aux | grep nfsd | sed /grep/d
   root 88 1 0 Jul 27 ? 0:01 nfsd

7. If nfsd is not running, type:

   # /usr/etc/nfsd 8 &

8. If nfsd is running, use the kill command with the PID to restart the daemon:

   # kill -HUP PID

Enabling TFTP

There are considerations to make if the boot or font host uses secure tftp.

To determine if you use secure tftp, check the file /etc/inetd.conf for a line similar to:

tftp dgram udp wait root /usr/etc/in.tftpd in.tftpd -s /tftpboot

tftp is one boot and file access method for network computers not equipped with DECnet or the ROM option. To use tftp to download the boot files from a host, or for font or any other file access, tftp service must be enabled on the host. For further information see the tftp man page for your host, or the supplied man page from /tekxp/man.

Use this procedure if you do not use SMIT:

1. The tftpd daemon should be started each time the host boots. The /etc/inetd.conf file is read at startup, and should contain the tftp command line. If the line does not exist in your inetd.conf file, you need to add it. To verify that the tftp startup command is in the file:

   # grep tftp /etc/inetd.conf

   tftp dgram udp wait nobody /usr/etc/tftp -n tftp

2. Verify that in.tftpd, the tftp binary, resides where it is specified in /etc/inetd.conf. For the preceding examples, tftp would be located in /usr/etc. If there is a mismatch between the actual location and the specified location, either move the binary or change the /etc/inetd.conf file.
3. Add entries to the /etc/tftpaccess.ctl file to identiify the secure directories on your host. See the tftpd man page for more details.

   Example:

   /etc/tftpaccess.ctl file

   allow:/tftpboot

   allow:/usr/tekxp

4. If you have edited inetd.conf, restart the inetd daemon for your changes to take effect:
   • Restart the inet subsystem:

     # inetimp

   • Restart inetd and read the inetd.conf file:

     # refresh -s inetd

Enabling BOOTP

Bootstrap protocol, bootp, is a method of ensuring that a particular network computer will always boot from the correct host using the proper configuration files. The bootpd daemon provides a name, IP address, boot path, and boot file name based on the hardware address of the network computer. Bootpd obtains booting data from the bootptab file. With the proper bootptab file and the network computer configured to boot from NETWORK, the network computer will boot from the network without any intervention, even for a first time boot.

1. Verify that the bootpd and bootptab files are in the /etc directory:

   # ls /etc/bootp*

2. If they are not there, copy the versions provided on the installation media:

   # cp /tekxp/bin/ibmRS6000/bootpd /etc
   # cp /tekxp/examples/bootptab /etc

3. Edit the /etc/hosts file to add the network computer IP addresses and names:

   128.07.60.30 portland
   128.07.60.31 corvallis

4. Update the arp table to add the new entries:

   # arp -s ether portland 08:00:11:01:00:45
   # arp -s ether corvallis 08:00:11:01:00:46

   The ether switch indicates you are providing a hardware address. The arp command also runs with a -f filename option, where filename is a file of all network computer entries to set.

5. Set up the bootptab file with the instructions presented in the next section.
6. Add the bootpd daemon start up to rc.tcpip:

   /etc/bootpd -s

7. Use the ps command to find the process ID number (PID) for bootpd. In this example the PID is 112.

   # ps aux | grep bootpd | sed /grep/d

   root 112 0.0 1.0 116 180 -S 10:0:01 0:00 /usr/etc/bootpd -s

8. Use the kill command with the PID to restart the bootpd daemon.

   # kill -9 PID

9. If bootpd is not running, type:

   # /etc/bootpd -s

Setting Up the bootptab File

The bootptab file contains the data used by bootpd. A sample bootptab file is located in /tekxp/examples. Refer to the bootpd man page in /tekxp/man for more information on the bootpd daemon provided on the installation media. The bootptab file contains three sections:

• Global template entries define general information about the host. They are used as part of the subnet template entries. Examples of global entries include:
  • Setting the subnet mask (sm).
  • Specifying the address for one or more Domain Name Servers (ds) if your site uses Domain Name Service (DNS) as an option.
  • Sets the network computer name (hn).
  • Sets the home directory (boot_directory) for the files (hd).
• Subnet template entries define information specific to each subnet. They are used for each network computer entry. Subnet template entries generally include:
  • Using the template command (tc) to point to the global entry.
  • Specifying the gateway or router to be used for each subnet (gw).
• Network computer entries are used to set information for a specific network computer. Network computer entries are specified by the network computer name and generally include:
  • Using the template command (tc) to point to the appropriate subnet entry.
  • Specifying the hardware type (ht), use ethernet for network computers.
  • Specifying the network computer's hardware (ethernet) address (ha).
  • Specifying the network computer's internet protocol address (ip).
  • Specifying the network computer's boot file (bf).
  • Specifying the location and name of the remote configuration file (T134).

Note:

T134 is a user-defined variable to the bootptab file. It is intended for use with the bootp and bootptab file included on the media.

Example 4-1 Sample bootptab File

# Global entries for all hosts
global.d:\
:sm=255.255.255.0:\
:ds=128.07.5.200 128.07.61.150:\
:hn:\
:hd=/tekxp:
#
# Master entries for each subnet template
subnet60: :tc=global.d:gw=128.07.60.100:
subnet61: :tc=global.d:gw=128.07.61.150:
#
# Individual network computer entries
# Sample entry for model type XP100, XP200, XP350, or XP400
portland: tc=subnet60:ht=ethernet:ha=080011010045:\
ip=128.07.60.30: bf=/boot/os.350:\
T134=config/admin.cnf:
# Sample entry for model type NC200 or NC400
corvallis: tc=subnet60: ht=ethernet: ha=080011010046:\
ip=128.07.60.31: bf=/boot/os.500:
# Sample entry for model type NC900
astoria: tc=subnet60: ht=ethernet: ha=080011010047:\
ip=128.07.60.32: bf=/boot/os.900:

Running BOOTP

There are two methods for using bootp:

• Always running the bootpd daemon so it is waiting for bootp requests.
• Only running the bootpd daemon when a process sends a bootp request.

Select the method that best fits your environment.

Always Running BOOTPD

1. If the bootpd daemon is started within the /etc/rc.tcpip file or a similar startup file, bootpd is always running and waiting for bootp requests. If the bootp command line does not exist in your /etc/rc.tcpip file, you need to add it. To verify that the bootpd -s startup command is in the file:

   # grep bootp /etc/rc.tcpip

   start /etc/bootpd -s ; echo -n ' bootpd'

   The -s option specifies continuous execution.

2. Verify that bootpd resides where specified in /etc/rc.tcpip. For the preceding examples, bootpd would be located in /etc. If there is a mismatch between the actual location and the specified location, either move the bootpd binary or change the /etc/rc.tcpip file.
3. The port numbers for bootp listening and replying must be set in the /etc/services file. If they are not set, edit the file and add them. To verify that the ports are set in the file:

   # grep bootp /etc/services

   bootps 67/udp
   bootpc 68/udp

4. To start the bootpd daemon without rebooting the system:

   # /etc/bootpd -s &

Only Running BOOTPD on Request

1. If the bootpd daemon is started without the -s option, it is only run when bootp requests are sent to the host. If the bootpd command line does not exist in your inetd.conf file, you need to add it. To verify that the bootpd - s startup command is in the file:

   # grep bootp /etc/inetd.conf
   
   bootps dgram udp wait nobody /etc/bootpd bootpd

2. Verify that bootpd resides where it is specified in /etc/inetd.conf. For the preceding examples, bootpd would be located in /etc. If there is a mismatch between the actual location and the specified location, either move the bootpd binary or change the /etc/inetd.conf file.
3. The port numbers for bootp listening and replying must be set in the /etc/services file. If they are not set, edit the file and add them. To verify that the ports are set in the file:

   # grep bootp /etc/services

   bootps 67/udp
   bootpc 68/udp

4. If you have edited inetd.conf, restart the inetd daemon for your changes to take effect:

Note:

In some installations, you may have to reboot the workstation to force a re-read of inetd.conf.

• Restart the Inet subsystem:

  # inetimp

• Restart inetd and read the inetd.conf file:

  # refresh -s inetd

Enabling XDM

The X Display Manager (xdm) provides services similar to a character terminal session, where a login window is displayed, error messages logged, and the operator's environment can easily be provided. The interface is customized through the use of several resource files.

This procedure enables the xdm program provided with the AIX 3.2 or later operating system. The procedure assumes that you have already built the Makefiles for the Xamples directory. If you have not, see /usr/lpp/X11/README for instructions. If the host is running xdm already, skip this section.

As root, do the following.

1. If you do not have a /usr/bin/X11 directory, make one.

   # mkdir /usr/bin/X11

2. Copy the xdm program to the /usr/bin/X11 directory.

   # cp /usr/lpp/X11/Xamples/bin/xdm    /usr/bin/X11

3. Set permissions for the new file.

   # chmod 755 /usr/bin/X11/xdm

4. If you do not have a /usr/lib/X11/xdm directory, make one.

   # mkdir /usr/lib/X11/xdm

5. Copy the xdm configuration files to the /usr/lib/X11/xdm directory.

   # cp /usr/lpp/X11/Xamples/clients/xdm/config/*    /usr/lib/X11/xdm

6. Set permissions for the new directory.

   # chmod 755 /usr/lib/X11/xdm/*

7. Using a text editor, open the /usr/lib/X11/xdm/Xsession file. The file should look similar to Example 4-2.

Example 4-2 Sample Xsession File

#!/bin/sh
#
# Xsession
#
case $# in
1)
case $1 in
failsafe)
exec xterm -geometry 80x24-0-0 -ls

        ;;

esac
esac

startup=$HOME/.xsession
resources+$HOME/.Xresources

if [  -f $startup  ]; then
exec $startup
exec /bin/sh $startup
else
if [  -f $resources  ]; then
xrdb -load $resources
fi
mwm &
exec xterm -geometry 80x24+10-10 -ls
fi

8. Edit the last four lines of the file to look like the example below. This change directs xdm to look at the system's xinitrc file to provide the user with the same environment as running xinit from the workstation console HFT.

   fi
   #mwm &
   #exec xterm -geometry 80x24+10-10 -ls
   /usr/lpp/X11/defaults/xinitrc
   fi

9. Save and exit the file.
10. Run the xdm daemon:

    # /usr/bin/X11/xdm -config     /usr/lib/X11/xdm/xdm-config

Adding DNS Entries

This section assumes that your site is currently running Domain Name Service (DNS). The instructions in this section deal strictly with adding network computer names and addresses to your existing zone and local host files on the name server. The following structure is used for the examples:

DOC 128.07.50.1 is the primary name server for the DOC company, oregon 128.07.60.1 is the secondary name server, serving the site's network computers, and portland 128.07.60.30 and corvallis 128.07.60.31 are network computers.

1. Edit the local host file for the name server. The typical file name is named.local. Depending on how you set up your system, the full path name for this example could be /var/named/oregon.DOC.COM/named.local. Add the network computer entries to the file. For example:

   ; named.local for server oregon
   IN NS oregon.DOC.COM
   30 IN PTR portland.oregon.DOC.COM
   31 IN PTR corvallis.oregon.DOC.COM

   IN indicates Internet Protocol, NS designates the name server, and PTR sets up reverse pointers for the network computers.

2. Edit the zone file for the name server. The typical file name is the name of your server. Depending on how you set up your system, the full path name for this example could be /var/named/hosts/oregon.DOC.COM. Add the network computer entries to the file. For example:

   ; zone hosts file for server oregon
   oregon A 128.07.60.1
   HINFO Sparc2
   portland A 128.07.60.30
   HINFO network computer
   corvallis A 128.07.60.31
   HINFO network computer

   A means IP address record; HINFO is an information entry.

3. Use the ps command to see if named is running:

   # ps aux | grep named | sed /grep/d
   root 88 1 0 Jul 27 ? 0:01 named

4. If named is not running, type:

   # named

5. If named is running, use the kill command with the PID to restart the daemon:

   # kill -HUP PID