Loading Linux On The First PC

RedHat Linux (Version 5.1) was first installed on the root PC. The instruction procedures are fairly well documented in the On-Line RedHat Manual available through www.redhat.com The descriptions below highlight, in particular, the specific selections made from the available software on the RedHat CDROM.

Contents

Preliminaries

Hrothgar was configured using the standard CDROM-based loading sequence:
  1. Insert the RedHat 5.1 CDROM into the PC.
  2. Boot the PC, using the supplied boot floppy.
  3. Answer the questions as they appear on the screen.
"User interactions" occur through a number of dialogue areas and buttons appearing on screens, such as in the sample screen shown here.

Sample RedHat Installation Screen

Navigation through these screens is fairly straightforward:

  1. The TAB key moves the cursor among the various buttons and user-entry fields.
  2. The ENTER key "pushes" a button.
  3. The Space Bar toggles entries for the Check Boxes.

Starting The Installation

The first several steps after rebooting from the RedHat boot floppy are straightforward:

  1. Choose a language for the installation program ("english" is the obvious choice, but you should probably bring up at least one of your nodes using "redneck").

  2. Select the keyboard type.

  3. PCMCIA Support (probably irrelevant/not needed).

  4. Selecting an Installation Method
    Choose Local CDROM for the first Beowulf node installation. Subsequent installations on nodes without CDROM drives will be done using NFS Image.

    Quoting, again, from the RedHat installation manual:

    "If you are going to install Red Hat Linux from CD-ROM, select ``CD-ROM'', and select Ok. The installation program will then probe your system, and attempt to identify your CD-ROM drive. It will start by looking for an IDE (also known as ATAPI) CD-ROM drive. If one is found, the installation will continue. If the installation program cannot automatically detect your CD-ROM drive, you will be asked what type of CD-ROM you have."

    (The automatic probing worked for installation on hrothgar).

  5. Select Install from the Installation Path dialogue box.

  6. SCSI Support. This was not needed for hrothgar.

Creating and Formatting Disk Partitions

The next stage in the installation is the creation of appropriate partitions on the hard drive, and the installation program will prompt for a choice between two partition utilities: Disk Druid and fdisk. Disk Druid was used for hrothgar.

The hard drives on the hrothgar nodes are all 3,022 Mbyte Western Digital, and Disk Druid was used to create three partitions on each of these drives:

  1. A 127 MByte swap partition (ideally, this should be as big as the amount of memory on the processor, but Disk Druid would not accept 128 Mbyte as an input).
  2. A 1 GByte Linux native partition, mounted as /.
  3. Everything else (about 1.87 GBytes) as a Linux native partition mounted as /scratch00 (partition naming conventions within hrothgar are discussed in the Know Your NFS/File Strategy setction of the Preliminaries document).
Each partition was created using the Add button from the main Disk druid panel, giving a dialogue box as shown below:

The mount point field is irrelevant for the Linux Swap partition. The "Growable?" toggle was checked for the last (/scratch00) partition so that it used all remaining space on the drive.

When all partitions are specified, clicking on the "Ok" button in the Disk druid main panel will start a disk formatting sequence, first for the swap space and then for the other hard drive partitions. On the first installation on any particular PC, it is probably best to toggle the "Check for bad blocks" flag (as well as the flags for all partitions) before clicking the "Ok" button. Note, however, that the check for bad blocks can be quite slow for a large drive, and the bad block check can usually be ignored on subsequent installations, if such re-installations prove necessary.

Selecting and Installing Software

The next step is specification of the software packages to be included in your installation, with the first menu listing a number of broad categories, as shown in the above figure. One option is to simply scroll down to the bottom of this menu, toggle the "Everything" option, and move on. However, this uses more than 600 Mbytes of the root partition, and includes a lot of stuff which is probably irrelevant (such as full HOWTO documentation in several different languages).

The strategy used in configuring hrothgar was to select relevant components from the first installation menu and toggle the "Select individual package" option before clicking the "Ok" button to start the selection of additional packages. The following subsections list the actual package selections used in configuring hrothgar.

Remarks:

  1. The F1 button can be used to provide some level of information on available packages during the installation sequence (although this information is fairly terse, and assumes the user knows a fair amount about standard packages - e.g., what curses is good for0.
  2. The software packages are installed using the (marvelous) RedHat Package Manager (RPM) system, and any packages which are accidentally missed during the installation can be added later using the RedHat Linux rpm command.
  3. A thinly annotated list of the available packages is available on-line in the Package Listing pages of the www.redhat.org site.
  4. Warning:The hrothgar selection lists given below are not guaranteed to be either complete or optimal, but it seemed to contain enough stuff to get the initial system running. Undoubtedly, it contains a lot of unnecessary stuff.

Selections From The "Components to Install" Menu

In addition to the "Select individual packages" toggle at the bottom of the menu, the selected packages from the main menu were as follows:

The last six items are additions to the default selection, and the default "Dialup Workstation" selection was deleted.

Individual Package Selections

With "Select individual packages" marked on, clicking on the "Ok" button of the main selection menu enables selections of individual software packages from a fairly large number of groups. The up and down arrows on the keyboard move the cursor among groups, and pressing the enter key presents a package list for the available group, as illustrated below. The arrows and spacebar are used to modify the package selection. Tabbing to "Ok" button and clicking completes the selection.

The individual package modifications/selections used in configuring hrothgar were as follows.

Applications/Communications Group

Added minicom, to enable serial communications (diagnostics) with the switch.

Applications/Editors

Added joe, emacs, emacs-X11

Applications/Math

Added gnuplot (MPICH has some nice performance/test utilities which produce gnuplot output).

Base/Kernel

Selected everything, enabling possible future tunings of the Linux kernel.

Development/Languages

Added egcs-g77, for fortran users.

Networking/Daemons

Not fully understanding the best network/NFS configurations for a Beowulf, we simply added a lot of stuff: autofs, am-utils, bootp, intimed, ypserve, xntp3. Undoubtedly, the package selection here could be simplified.

After all relevant individual packages were selected, the "Ok" button on the Select Group panel was clicked. In our case, this produced a new Unresolved Dependencies panel listing a few additional packages required for a consistent installation. Clicking the "Ok" button on this panel started the actual installation which, in our case, took about 12 minutes.

Finishing Up

After the selected packages were loaded, The RedHat installation procedure goes through a number of straightforward final steps. The discussions below are brief summaries of material from Section 5 of the RedHat Installation Manual.

  1. Configuring a Mouse: The installer will probe for and set parameters for your mouse.

  2. Configuring X Windows: The Xconfigurator utility is run to attempt to determine and configure the card. The installer will ask for information on your monitor.

  3. Configuring Networking: Hrothgar was configures using the Static IP address option from the window which appears at this point. The system prompts for a number of standard IP data, as described in the Know Your Network section of the Preliminaries page.

    The network numbers entered at this point were for the "external" LAN of the hrothgar system, not the "internal" (192.168.8.) addresses used for the network among the individual hrothgar PCs.

  4. Configuring the Clock: Enter some obvious data to specify your time zone.

  5. Selecting Services for Start on Reboot: A simple Services menu is presented, asking which of the configured services should be started automatically each time the system is rebooted. Lacking any real idea what to do here, we simply selected everything. This is probably not quite right, and the unnecessary services (once identified) can/will be disabled by editing the configuration files in /etc/rc.d/init.d.

  6. Setting a Root Password: Obvious.

  7. Creating a Boot Diskette: A good backup strategy (remove the floppy once this finishes).

  8. Installing LILO: Installing LILO (the LInux LOader) in the Master Boot Record is the usual way of ensuring that Linux is loaded automatically whenever the system is rebooted.

The PC should next reboot itself, and come up with a unix login prompt. Login as root, ...