3. Configuring the AS/400

You definitifly need to be QSECOFR or equivalent on the AS/400 to do that. If you want to use DHCP you'll also need to use Client Access Operations Navigator.

3.1 Security issues

The NFS file system performs security checks based on IP addresses. This is only an acceptable security method for systems in a protected environment, meaning that the network cable of the card in the IPCS server should be connected to a network card used solely for that purpose on the AS/400, else there is a risk of other machines in the LAN faking the same address to modify the linux filesystem image file.

Since there is no ``arp''-command on the AS/400 there is no way of statically assigning an IP address to a ethernet hardware address (MAC).

3.2 Remote boot Directories

We need some directories to store configuration files in:

   mkdir '/linux'
   chgaut '/linux' *public *rx
   mkdir '/linux/netfinity'
   mkdir '/linux/bt'
   mkdir '/linux/pxelinux.cfg'

3.3 DHCP

You only need to care about DHCP if you're using the 3COM remote boot sequence. If you use the PC-DOS/loadlin boot sequence you won't need to care about that.

OS/400 essentially requires Client Access Operations Navigator for DHCP configuration, since there is no syntax description for the config file available and there are no means of entering data anywhere.

DHCP configuration data is essentially stored in the file /QIBM/UserData/OS400/DHCP/dhcpsd.cfg.

Here is a piece of configuration showing the neccessary entries:

   subnet 10.4.1.0 255.255.255.0 10.4.1.30-10.4.1.40  (alias="herdsoft"
   {
     option 3 10.4.1.104
     option 6 10.4.1.104
     option 15 herdsoft
     option 1 255.255.255.0
     option 67 /linux/bt/pxelinux.bin
     client 1 0050da4f56ec 10.4.1.30 (alias="netfinity"
   }

Option 67 informs the boot ROM about the name of the file to download via TFTP and start. The filename used depends on the bootcode to be used, since the 3Com card selected is PXE compliant we're using pxelinux.bin from the SYSLINUX package.

The client needs to have a unique IP address, don't try to get it automatically from the pool.

Remember to make DHCP automatically start on IPL using the OS/400 command CHGDHCPA.

Remember to place an entry for the IP address into your DNS server.

3.4 TFTP

You only need to care about DHCP if you're using the 3COM remote boot sequence. If you use the PC-DOS/loadlin boot sequence you won't need to care about that.

Use the OS/400 command CHGTFTPA to set ALTSRCDIR to /linux/bt:

CHGTFTPA AUTOSTART(*YES) ALTSRCDIR('/linux/bt')

3.5 NFS

NFS/400 uses /etc/exports on the AS/400 as it's config file. Some options useful for best performance are not reachable by the client access operations navigator.

In case you don't know how to edit a file from the AS/400 console, try:

   crtlib gptools text('from QGPL/QGPTOOLS *SAVF')
   rstobj *all qgptools *savf savf(qgpl/qgptools) rstlib(gptools)
   addlible gptools
   edtf '/etc/exports'

Add something like the following at the end of the file:

/linux/netfinity ROOT=netfinity.herdsoft:tux.herdsoft:redhat.herdsoft   \
  #HOSTOPT HOSTNAME=TUX.HERDSOFT, DATAFILECODEPAGE=65535, PATHNAMECODEPAGE=850,
NOWAITFORWRITES

An control to activate NFS startup on IPL is available in the Client Access Operations Navigator. I have not found a pedant on the console.