Appendix B. Sample Parameter Files

The IBM S/390(R) and IBM eServer zSeries(R) architectures use a special parameter file to set up networking before the installation program (anaconda) can be started. This section describes the contents of the parameter file.

The parameter file has a limit of 32 total parameters. To accommodate limitations of the parameter files, a new configuration file on a CMS DASD should be used to configure the initial network setup and the DASD specification. The .parm file should contain the real kernel parameters, such as root=/dev/ram0 ro ip=off ramdisk_size=40000, and single parameters which are not assigned to variables, such as vnc. Two new parameters which point the installation program at the new configuration file need to be added to the .parm file. They are CMSDASD and CMSCONF.


Where <cmsdasd_address> represents the list of the device ID of the CMS DASD device which contains the configuration file. This is usually the CMS user's 'A' disk. This option is applicable only for users who have a CMS formatted disk (z/VM) available.

For example: CMSDASD=191


Where <configuration_file> represents the name of the configuration file. This value must be specified in lower case. It is specified in a Linux style file name format. The CMS file REDHAT CONF is specified as redhat.conf. This option is applicable only for users who have a CMS formatted disk (z/VM) available.

For example: CMSCONFFILE=redhat.conf


Where <dasd-list> represents the list of DASD devices to be used by Red Hat Enterprise Linux.

Although automatic probing for DASDs is done if this parameter is omitted, it is highly recommended to include the DASD= parameter, as the device numbers (and therefore the device names) can vary when a new DASD is added to the Red Hat Enterprise Linux guest. This can result in an unusable system.

For example: DASD=0.0.0100,0.0201-0.0.0204

The following parameters are required to set up networking:


Provides required device bus IDs for the various network interfaces.

qeth: SUBCHANNELS="<read_device_bus_id>,<write_device_bus_id>,
lcs: SUBCHANNELS="<read_device_bus_id>,<write_device_bus_id>"
ctc: SUBCHANNELS="<read_device_bus_id>,<write_device_bus_id>"

Due to the length of the qeth command line, it has been broken 
into two lines.  

For example (a sample qeth SUBCHANNEL statement):


To force a specific CTC protocol, additional parameters can be added. For example:


where <n> is one of the following:

  • 0 for compatibility mode (used with non-Linux peers other than S/390 and zSeries operating systems)

  • 1 for extended mode

  • 2 for CTC-based tty (only supported on Linux-to-Linux connections)

  • 3 for compatibility mode with S/390 and zSeries operating systems


Where <userid> represents the ID of the guest machines you want to connect to. Note that the ID must be written in capital letters. For example, an IUCV connection to a z/VM TCP/IP service machine would be written as:


The following parameters are optional:


Where <string> is the hostname of the newly-installed Linux guest.


Where <type> must be one of the following: ctc, iucv, qeth or lcs.


Where <IP> is the IP address of the new Linux guest.


Where <network> is the address of your network.


Where <netmask> is the netmask.


Where <broadcast> is the broadcast address.


Where <gw> is either the gateway-IP for your eth device or the IP address of the ctc/escon/iucv point-to-point partner.


Where <mtu> is the Maximum Transmission Unit (MTU) for this connection.


Where <server1>:<server2>:...:<serverN> is a list of DNS servers, separated by colons. For example:


Where <domain1>:<domain2>:...:<domainN> is a list of the search domains, separated by colons. For example:
PORTNAME=<osa_portname> | <lcs_portnumber>

This variable supports OSA devices operating in qdio mode or in non-qdio mode.

When using qdio mode: <qeth_portname> is the portname specified on the OSA device when operating in qeth mode. PORTNAME is only required for z/VM 4.3 or older without APARs VM63308 and PQ73878.

When using non-qdio mode: <lcs_portnumber> is used to pass the relative port number as integer in the range of 0 through 15.

FCP_* (FCP_1, FCP_2, ...)

These variables can be used on systems with FCP devices to preconfigure the FCP setup (these can be changed during the installation).

Use the following samples as a guide to formatting proper parameter files.

Sample file with minimally required parameters:

root=/dev/ram0 DASD=200


The Red Hat Enterprise Linux installation program prompts the user for any required parameters not specified in the parameter file.

Sample file configuring a CTC networking device:

Example of redhat.parm file:

root=/dev/ram0 ro ip=off ramdisk_size=40000

Example of redhat.conf file (pointed to by CMSCONFFILE in redhat.parm)