6.2 Prepare for Linux installation

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The steps involved in preparing for a Linux installation are as follows:

Obtain a Linux distribution.
Obtain the necessary networking resources and information.
Mount the Linux CDs and set up an NFS or FTP server.
Fill in the Linux installation worksheet.

6.2.1 Obtain a Linux distribution

Table 6-1lists the 31-bit Linux distributions that are available for zSeries.

Table 6-1: Linux for zSeries distributions
Distribution	Kernel level	Date of build (per uname -v)
Debian 3.0	2.4.17	Dec. 16, 2002
Red Hat 7.2	2.4.9	Nov. 23, 2001
SuSE Linux	2.2.16	Nov. 5, 2000
SuSE SLES-7	2.4.7	Oct. 30, 2001
SuSE SLES-8 (United Linux 1.0)	2.4.17	Nov. 6, 2002
SuSE SLES-8, with Service Pack 2	2.4.19	June 5, 2003
TurboLinux TLES-8 (UnitedLinux 1.0)	2.4.17	Oct. 30, 2001
TurboLinux TLES-8 with Service Pack 2	2.4.19	June 5, 2003

There are other Linux distributions for zSeries that are not commonly used, or are no longer available. They include Caiman Linux, Millenux Linux, and the Marist filesystem.

Domino for zSeries is not supported on any 64-bit Linux distributions.

Important:

Domino 6.5 needs the new sys_epoll thread pooling code. Notes clients will not connect to the server if this code is not in place. Of all the distributions listed above, only United Linux 1.0 (31-bit SuSE SLES-8 and Turbolinux TLES-8) with Service Pack 2 has this function, at the time of writing.

The Web site for the SuSE SLES-8 zSeries distribution is:

http://www.suse.com/us/business/products/server/sles/s390.html

6.2.2 Obtain the necessary networking resources and information

You will need at least one networking device to install Linux on zSeries. Often this is a directly connected OSA or a z/VM guest LAN, both of which are usually defined by three zSeries addresses. For additional information on networking, see Chapter 5, "Networking" on page 71.

You will need at least one TCP/IP address and the usual related TCP/IP information, such as the gateway TCP/IP address, the DNS TCP/IP address, the subnet mask, and the MTU size.

You will need a host name for the Linux image. It is useful to have it in the Domain Name Services (DNS) ahead of time, but not required.

6.2.3 Mount the Linux CDs and set up an NFS or FTP server

Usually the Linux RPMs are copied from an NFS or FTP server. It can be a Linux on zSeries, however, you run into a "chicken and egg" problem: if you need a Linux FTP or NFS server to install zSeries Linux, then how do you install the first copy? For this reason, often a Linux distribution is installed on a PC first. If you are going to do this, it is recommended that you install the same distribution on a PC that you will be installing on zSeries. Then you have to make the CDs available by setting up either an NFS or FTP server.

Attention:

An NFS server is recommended over an FTP server because it makes applying SLES-8 service pack 2 (sp2) easier—but either method will work.

Making the Linux CDs available

SuSE SLES-8 consists of three installation CDs, two supplemental CDs and service pack 2 (sp2) CD. You need at least installation CDs 1 and 2, and probably CD 3, to install Linux. The supplemental CDs are not required; however, some useful packages such as cpint are on them.

It is recommended that the physical CDs be copied to .iso files (also called ISO images). This avoids the need to constantly have to change CDs in the drive. To convert physical CDs to ISO images, put each CD in the drive and use the dd command. For example:

    # cd /sles8    # dd if=/dev/cdrom of=/SLES-8-s390-Int-RC6-CD1.iso

Note

Some Linux systems do not have a device file named /dev/cdrom, even though they have a physical CD drive. If so, you should determine the name of the CD drive.

When you have created ISO images for all necessary CDs, they must be mounted loopback. This is done with the -o loopback parameter to the mount command.

You will also want the filesystem to be mounted read-only, which is the nature of a CD, and you will want empty directories over which to mount(by convention, this is under the /mnt directory).

An example of mounting four ISO images loopback is shown here. After you are finished, verify that the CDs are mounted:

    # cd /mnt    # mkdir sles8cd1 sles8cd2 sles8cd3 sles8sp2    # cd /sles8    # mount -o loop,ro /SLES-8-s390-Int-RC6-CD1.iso /mnt/sles8cd1    # mount -o loop,ro /SLES-8-s390-Int-RC6-CD2.iso /mnt/sles8cd2    # mount -o loop,ro /SLES-8-s390-Int-RC6-CD1.iso /mnt/sles8cd3    # mount -o loop,ro /SLES-8-s390-Int-RC6-CD1.iso /mnt/sles8cd1    # mount | grep sles8    /sles8/SLES-8-s390-Int-RC6-CD1.iso on /mnt/sles8cd1 type iso9660    /sles8/SLES-8-s390-Int-RC6-CD2.iso on /mnt/sles8cd2 type iso9660    /sles8/SLES-8-s390-Int-RC6-CD3.iso on /mnt/sles8cd3 type iso9660    /sles8/SLES-8-SP2-s390.iso on /mnt/sles8sp2cd1 type iso9660

The next step is to set up either an NFS (recommended) or FTP server.

Set up an NFS server

In most SLES-8 installs, the NFS server is installed but not started. This is verified by the rpm and rcnfsserver commands:

    # rpm -qa | grep nfs-utils    nfs-utils-1.0.1-25    # rcnfsserver status    Checking for kernel based NFS server:                        unused

Unlike inetd, the NFS server cannot run standalone. It also requires the nfslock service to be running. Use the chkconfig command to query whether these services are configured to run:

    # chkconfig | grep nfs    nfs                       off    nfslock                   off    nfsserver                 off

In this example, they are not. They can be turned on with the chkconfig command:

    # chkconfig nfslock on    # chkconfig nfsserver on

Now the directories that are to be exported through NFS must be set. This is done in the configuration file /etc/exports. Add a line for each directory you wish to export. The value *(ro) means that any workstation with an NFS client can have read-only access to the directory

    # cd /etc    # vi exports             // add 4 lines    # See the exports(5) manpage for a description of the syntax of this file.    # This file contains a list of all directories that are to be exported to    # other computers via NFS (Network File System).    # This file used by rpc.nfsd and rpc.mountd. See their manpages for details    # on how make changes in this file effective.    /mnt/sles8cd1       *(ro)    /mnt/sles8cd2       *(ro)    /mnt/sles8cd3       *(ro)    /mnt/sles8sp2       *(ro)

Now start the NFS server for this session with the rcnfsserver command:

    # rcnfsserver status    Checking for kernel based NFS server:                        unused    # rcnfsserver start    ...                                                                 done

You should now be able to mount these directories remotely using NFS.

Set up an FTP server

Either an NFS or FTP server can be used. Both work well. There are various trade-offs which are negligible. Setting these services up depends on the specifics of your distribution.

In order to set up an FTP server on SLES-8, the following steps are performed. First check that an FTP server is installed with the rpm -qa command piped to grep:

    # rpm -qa | grep ftpd    vsftpd-1.1.0-21

The FTP server is typically started from the Internet super-server inetd (though some systems use xinetd, which often has a configuration directory, /etc/xinetd/), so verify that inetd is running. If it is not (as is the case with SLES-8), it can be set to start with the chkconfig command:

    # rcinetd status    Checking for inetd:                                          unused    chkconfig inetd on

Now the FTP server must be set to listen in the /etc/inetd.conf file. This is done by uncommenting one line (delete the leading #):

    # cd /etc    # vi inetd.conf           // uncomment one line    ...    # These are standard services.    #    # ftp   stream tcp      nowait  root   /usr/sbin/tcpd  in.ftpd    ftp     stream tcp      nowait  root   /usr/sbin/tcpd  vsftpd    ...

By default, the vsftpd daemon only allows anonymous FTP. This must be changed in the /etc/vsftpd.conf file:

    # vi vsftpd.conf            // uncomment two lines    # Example config file /etc/vsftpd.conf    #    # The default compiled in settings are very paranoid. This sample file    # loosens things up a bit, to make the ftp daemon more usable.    #    # Allow anonymous FTP?    anonymous_enable=YES    #    # Uncomment this to allow local users to log in.    local_enable=YES    #    # Uncomment this to enable any form of FTP write command.    write_enable=YES    ...

Now start the inetd server manually:

    # rcinetd start   Starting inetd                                      done

Now you should be able to FTP in as a non-root user. If you also want to FTP in as root, delete or comment the root entry in the /etc/ftpusers file.

Fill in the Linux installation worksheet

You should now have enough information to fill in the worksheet in Table 6-2. This worksheet will be handy when you start the Linux install.

Table 6-2: Linux installation worksheet
Description	Value
REXX EXEC to IPL from reader (under z/VM only)
OSA or Guest LAN addresses (usually three)
OSA Express port name (for OSA devices only)
Fully qualified host (DNS) name
Linux IP address
Subnet mask
Gateway IP address
DNS server IP address
MTU size
NFS or FTP server with install CDs
File path to distribution CD
File path to SP2® update CD
FTP server user ID/password (for FTP server only)
Installation method (X Window, VNC or ssh)
TCP/IP address of X server (X Window method only)
DASD addresses to be used

You may also want to write down each DASD and corresponding device and filesystem that will be used. When the Linux DASD device driver adds DASD, it takes the addresses and sequentially assigns them to files in the /dev directory starting at dasda, then to dasdb, and so on. The 27th and 28th DASD are assigned to /dev/dasdaa and /dev/dasdab, and so on.

Table 6-3 contains a worksheet that you may find useful to fill in to describe which filesystems the various DASD should be mounted over.

Table 6-3: DASD and filesystem worksheet
DASD address	Linux device file name (for example, /dev/dasda)	Filesystem over which to mount

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