Subsections


7.3 Cluster Definition

During this phase, you will complete steps 1 through 6 of the OSCAR wizard in defining your cluster. If you encounter problems or wish to redo any of the SIS actions performed in the wizard steps 2 or 3, please refer to the SIS(1) man pages.


7.3.1 Step 1: Prepare OSCAR server for install

Begin the installation process by pressing the Step 1 button of the wizard entitled $<$Prepare OSCAR Server for Install$>$.

Here you will select the default MPI implementation for use on the cluster. Note that all available MPI implementations will be available for general use; this step simply picks which one will be the system default.

This step also installs and starts other necessary software, devices, and services on the server.


7.3.2 Step 2: Build the Image

Press the Step 2 button of the wizard entitled $<$Build OSCAR Client Image$>$. A dialog will be displayed. In most cases, the defaults will be sufficient. You should verify that the disk partition file is the proper type for your client nodes. The sample files have the disk type as the last part of the filename. You may also want to change the post installation action and the IP assignment methods. It is important to note that if you wish to use automatic reboot, you should make sure the BIOS on each client is set to boot from the local hard drive before attempting a network boot by default. If you have to change the boot order to do a network boot before a disk boot to install your client machines, you should not use automatic reboot.

Building the image may take several minutes; the red progress bar on the bottom of the window will indicate how far along the process is.

There is a lot of output in the console window during the build. It is normal to see some warning messages in the console. You can safely ignore these messages and wait for the final popup window announcing the success or failure of the overall image build.

A sample dialog is shown in Figure 2.

Figure 2: Build the image.
Image 4a_sbs-build-image1

7.3.2.1 Customizing your image.

The defaults of this panel use the sample disk partition and RPM package files that can be found in the oscarsamples directory. You may want to customize these files to make the image suit your particular requirements.

7.3.2.1.1 Disk partitioning.

The disk partition file contains a line for each partition desired, where each line is in the following format:

  <partition> <size in megabytes> <type> <mount point> <options>

Here is a sample (for a SCSI disk):


/dev/sda1 	24            ext2		/boot defaults
/dev/sda5	128          swap
/dev/sda6	1000        ext2		/     defaults
nfs_oscar:/home  -          nfs                /home  rw

The last partition specified will grow to fill the entire disk. You can create your own partition files, but make sure that you do not exceed the physical capacity of your client hardware. Also be careful to not specify duplicate filesystems as this will cause problems during the installation. The sample listed above, and some others, are in the oscarsamples directory.

7.3.2.1.2 Package lists.

The package list is simply a list of RPM file names (one per line). Be sure to include all prerequisites that any packages you might add. You do not need to specify the version, architecture, or extension of the RPM filename. For example, bash-2.05-8.i386.rpm need only be listed as ``bash''.

7.3.2.1.3 Custom kernels.

If you want to use a customized kernel, you can add it to the image after it is built (after step 1, but before step 2). See the kernel_picker application description in Section 8.3 on page [*].

7.3.2.1.4 Build the Image.

Once you are satisfied with the input, click the $<$Build Image$>$ button. When the image completes, a popup window will appear indicating whether the build succeeded or failed. If successful, click the $<$Ok$>$ button, and you will be returned to the main OSCAR wizard menu.

If the build fails, look through the console output6 for some indication as to what happened to cause the failure. Common causes include: prerequisite failure, ran out of disk space, and missing package files. Also see the Release Notes for this version of OSCAR in Section 3 (page [*]).


7.3.3 Step 3: Define your client machines

Press the Step 3 button of the wizard entitled $<$Define OSCAR Clients$>$. In the dialog box that is displayed, enter the appropriate information. Again the defaults will be correct in most cases. At a minimum, you will need to enter a value in the Number of Hosts to specifies how many clients you want to create.

  1. The Image Name field should specify the image name that was used to create the image in Step 2.

  2. The Domain Name field should be used to specify the client's IP domain name. It should contain the server node's domain (if it has one); if the server does not have a domain name, the default name oscardomain will be put in the field (although you may change it). This field must have a value - it cannot be blank. Note that especially for compute nodes on a private network, the domain name does not necessarily matter much. The domain name supplied in this field is used to form the fully-qualified name of each host in the OSCAR cluster. For example: oscarnode1.oscardomain, oscarnode2.oscardomain, etc. If your compute nodes are on a public network, you may want to use the ``real'' domain name that is part of their fully-qualified domain names.

  3. The Base name field is used to specify the first part of the client name and hostname. It will have an index appended to the end of it. This name cannot contain an underscore character ``_''.

  4. The Number of Hosts field specifies how many clients to create. This number must be greater than 0.

  5. The Starting Number specifies the index to append to the Base Name to derive the first client name. It will be incremented for each subsequent client.

  6. The Starting IP specifies the IP address of the first client. It will be incremented for each subsequent client. See Footnote 4 on page [*] for more information on how to pick a starting IP address.

  7. The Subnet Mask specifies the IP netmask for all clients. See Footnote 5 on page [*] for more information on how to select a netmask for your cluster.

  8. The Default Gateway specifies the default route for all clients.

When finished entering information, press the $<$Addclients$>$ button. A sample dialog is shown in Figure 3.

After the clients are created, a dialog will pop up with the completion status. After closing that, you may press the $<$Close$>$ button in the build clients dialoge and continue with the next step.

Figure 3: Define the Clients.
Image 5a_sbs-define-clients1


7.3.4 Step 4: Collect client MAC addresses and Setup Networking

The MAC address of a client is a twelve hex-digit hardware address embedded in the client's ethernet adapter. For example, `` 00:0A:CC:01:02:03'', as opposed to the familiar format of IP addresses. These MAC addresses uniquely identify client machines on a network before they are assigned IP addresses. DHCP uses the MAC address to assign IP addresses to the clients.

In order to collect the MAC addresses, press the Step 4 button of the wizard entitled $<$Setup Networking$>$. The OSCAR network utility dialog box will be displayed. To use this tool, you will need to know how to network boot your client nodes. For instructions on doing so, see Appendix A. A sample dialog is shown in Figure 4.

To start the collection, press the $<$Collect MAC Address$>$ button and then network boot the first client. As the clients boot up, their MAC addresses will show up in the left hand window. Select a MAC address and the appropriate client in the right side window. Click $<$Assign MAC to Node$>$ to associate that MAC address with that node. If you would like to make specific nodes associated with specific client definitions, you should boot them one at a time. If you do not care which node gets associated with which client, you may boot them all at once and randomly assign the MAC addresses.

When you have collected all of the MAC addresses, click the $<$Stop Collecting$>$ button and then click the $<$Configure DHCP Server$>$ button to configure the DHCP server.

You may also configure your remote boot method from this panel. The $<$Build Autoinstall Floppy$>$ button will build a boot floppy for client nodes that do not support PXE booting. The $<$Setup Network Boot$>$ button will configure the server to answer PXE boot requests if your client hardware supports it. See Appendix A for more details.

When you have collected the addresses for all your client nodes and completed the networks setup, press the $<$Close$>$ button.

Figure 4: Collect client MAC addresses.
Image 6e_sbs-found-mac

root 2002-11-08