This chapter describes what you need to know before you begin to run SystemImager and how to start the tool. The remainder of the chapter provides a description of the main window and each of the tasks that SystemImager performs.
The SystemImager tool enables you to replicate the data you have configured on the golden master to each client in a set of Linux machines. This replication process overwrites and repartitions the client disk. Subsequently, you can use the synchronization feature of this tool to change the content of any or all of the replicated clients.
Before you begin running SystemImager, ensure that the console (if there is one), server, golden master, and client(s) are connected to the network with the necessary software and that the golden master has been configured with all of the components and characteristics that you want your clients to have. For specific files to install, refer to Chapter 3, “Installing SGI SystemImager”.
To start SystemImager, log onto the console machine. An SGI SystemImager icon will appear in the applications section of your KDE or GNOME Start menu. If you cannot find the icon, run the following command:
After you have started SystemImager, a login dialog box appears, allowing you to establish a connection to a server. You must provide the following information:
Server name is the name of the machine that holds the images and synchronizes the clients.
Login name is either root or the user account name that will be used to administer the server.
Password is the password for the root or the user account.
When you have provided this information, click the OK button. There is also a Help button and a Cancel button.
The main SGI SystemImager window (see Figure 4-1) is divided into client view, configurations area, and task buttons.
The client view area shows the list of clients in the cluster in the form of icons with labels. This area is labeled “Clients.” When you bring up SystemImager for the first time, this area is blank because you have not yet defined the clients. When icons are present, clicking on the icon or the icon's label displays a small window with the following information about the client:
When the main window first comes up, the Configurations area displays the configuration fields and their current or default values. This area is labeled “Overview and Configuration Parameters.” For more information about any of the configuration fields and their possible values, simply click on the field label to pop up a glossary window. These fields are not editable from the main window. To edit these fields, use the Configure Parameters task (see “Configure Parameters”).
When you activate a task (see “Task Button Area”), the activated task covers the Configurations area. When the task is done, the configuration fields and their values appear again. If you used the task to change the value of any configuration field, that new value appears.
The Task Button area contains a button for each task that SystemImager performs. The buttons are placed in the general order in which you will perform the tasks. If you are running SystemImager for the first time, you must configure the clients before configuring parameters or performing any of the other tasks. If you attempt to perform a task that depends on the results of another task, you will receive a warning that the prerequisite task has not yet been performed. For a description of each task, see “Tasks”. To activate a task, click on the task button. The content of the task is displayed in the Configurations area. While a task is running, the other task buttons are unavailable.
Each task contains editable fields. The labels for the fields are displayed in blue, indicating that you can click on them. Clicking on a blue label brings up a pop-up window that contains a description of the field. The fields whose labels are displayed in italic font are optional and can be left blank. When you edit a field whose label is marked with an asterisk (*), the value that you supply applies only for the duration of that task.
At the bottom of each task are OK, Cancel, and Help buttons. When you click OK, the task is performed, using the parameters you specified. When you click Cancel, the task exits with no action performed. When you click Help, a help window appears with the appropriate help for that task.
Each task ends with either a result dialog box when it completes successfully or an error message dialog box if it fails. If the task fails, you can try changing the data you entered and try clicking OK again. When the task completes successfully and you dismiss the dialog box, the Configurations area replaces the task and the task buttons are available again.
The following sections describe the SystemImager tasks.
The Configure Client List task lets you define the clients in the cluster. Whenever you reconfigure the machines in your cluster, you must update this list. The information you supply for this task is used subsequently to synchronize the clients (see “Synchronize Clients”).
To add a client to the cluster, enter the client hostname, IP address, and Ethernet address in their respective boxes and click on the Add button. When you enter this information, it will appear in the list under the boxes. If you do not know the Ethernet address, you can obtain it in one of the following ways:
If the client is running Linux, log in to the client and enter the following command:
The Ethernet address will be listed in the following format:
If the client is not running Linux, boot your distribution's boot CD, go to rescue mode (for example, on RedHat, enter linux rescue at the prompt), and run ifconfig as described in the previous example.
If you need to make changes to the listed information, use the Modify button and then enter your changes. To delete a client from the list, highlight the client and use the Delete button.
After you click OK and the clients are added successfully, SGI SystemImager adds to the /etc/hosts file any clients that are not already in /etc/hosts or in the NIS database.
The Configure Parameters task lets you specify default values for the following parameters. Some of these values can be changed from other tasks but those changes last only for the duration of the task in which they are changed.
Default client gateway IP address - An address in dot notation, such as 18.104.22.168. This parameter is optional and can be left blank. The client gateway IP address is the gateway address that the tool will configure the clients to use. For gateway information, check with your network administrator.
Default client netmask - A value in dot notation, such as 255.255.255.0. The default client netmask is the netmask that the tool will configure the clients to use. For netmask information, check with your network administrator.
Default floppy drive device - A value such as /dev/fd0. The floppy drive device will be used by the server when the Create Boot Diskette task is used to create a bootable floppy disk. The location of the device is permanent unless changed by the Configure Parameters task.
Default image name - A name such as image1 (you can select the name from the menu). The image name is the name of a copy of the hard disk of the golden master machine. The default image is the image that will be used to update the clients during synchronization. If there are no images created yet, this field should be left blank.
Default synchronization group size - A number that represents the number of clients to be synchronized at a time, such as 10. If the actual number of clients to be synchronized exceeds this number, the additional clients are synchronized one by one, as the other client synchronizations finish. The sychronization process puts a lot of traffic on the network and load on the server, so it is important to choose the number of clients that your network and server can handle.
During initial replication with the boot diskette, the entire image from the golden master is replicated to all of the clients. For subsequent synchronizations via the Synchronize Clients task, you can use the Modify Exclusion List task to specify files and directories that are not to be replicated from the golden master to the clients. Adding a file or directory to the exclusion list modifies the exclusion list on the golden master. However, when you add a file or directory to the exclusion list, that file or directory does not actually get excluded from replication until the following tasks have been performed:
You must run the Prepare Image task to update the image on the server. The modified exclusion list will be copied to the server along with any other changed files as part of the image. However, the Prepare Image task does not check the exclusion list that it puts on the server, so the file or directory that you have added to the exclusion list is not yet excluded.
You must then run the Synchronize Clients task to copy the image (including the exclusion list) to the clients. The Synchronize Clients task does check an exclusion list, but the exclusion list it checks is the list that is already on the client's disk, not the new one that is being copied to the disk. So the file or directory that you have added to the new exclusion list is not yet excluded.
The next time you run the Synchronize Clients task, the exclusion list that the task checks is the one with your file or directory added. Now your file or directory is excluded from replication.
Each line that you enter in the Exclusion list box must be the full path name of either a file or a directory (for example, /usr/tmp). Blank lines and lines that begin with "#" are treated as comments.
The Prepare Image task lets you create or update an image of the golden master. If you want to create a new image, you need to have enough free disk space on the server to hold the disk image of the golden master. Creating a new image can take a while, depending on the size of the disk.
In this task, you must specify the name of the golden master. (The new name of the golden master lasts for the duration of this task only.) Then indicate whether you are creating a new image or updating an existing image by selecting the appropriate button. You must also specify the name of the image to be created or updated. If you are creating a new image, enter the new name. If you are updating an existing image, either enter the name of the existing image or select a name from the menu.
If you want this image to be the default, click the Set image to be default checkbox on. If there is no existing image, the new image to be created will be the default image.
The Create Boot Diskette task lets you create a boot diskette to be used for replicating a client for the first time. If your clients are SGI 1200 machines, you have an option to boot the clients over the network. Whether you are booting with the diskette or over the network, before you can replicate a client, you must have at least one image prepared and a default image set. To create and set up an image, see “Prepare Image”. To set or change the default image, see “Configure Parameters”.
To create the boot diskette, either supply the floppy drive device name, such as /dev/fd0, in the indicated box or use the default. (Changing the name of the floppy drive device lasts for the duration of this task only.) Before pressing OK, remember to insert a blank diskette.
The Synchronize Clients task lets you use an image file (that you created using the Prepare Image task) to resynchronize the clients. You must specify the image file in the Image name box by entering the image name or by selecting an image from the menu. (A new image name lasts for the duration of this task only.)
Indicate the number of clients to be synchronized at one time in the Synchronization group size box. The sychronization process puts a lot of traffic on the network and load on the server, so it is important to choose the number of clients that your network and server can handle. Consider the amount of data to be synchronized and the total number of clients to be synchronized. The default synchronization group size is 10. (A new synchronization group size lasts for the duration of this task only.)
To indicate the names of clients to synchronize, use the Clients to synchronize box. Enter the names of the clients to be synchronized or select them from the menu and click on the Add button. If you are synchronizing all of the clients, simply click on the All button.
To delete a client, use the Delete button. To clear the entire list, use the Clear button.
This section provides steps for replicating a client for the first time with a boot diskette or over the network.
After you have created the boot diskette (see “Create Boot Diskette”) and a default image is set up, to complete the replication process, perform the following steps:
Insert the diskette into the disk drive of the server, which, if your console is not the same as your server, will not be the machine on which the SGI SystemImager GUI is running.
The boot diskette that is created will work for all clients. The image that will be transferred to the client is determined by the default image on the server when the diskette is booting.
Insert the diskette into a client machine and reboot. The image designated as the default image will be replicated onto the client.
After the replication is complete, remove the diskette and reboot the client again.
This section provides a guide for using SGI SystemImager to perform common system administrator tasks.
If you want to . . .
Follow these steps . . .
Set up a new cluster
1. Use the Configure Client List task to define all clients.
2. Use the Configure Parameters task to specify parameters for your environment.
3. Use the Modify Exclusion List task to specify files or directory to be excluded.
4. Use the Prepare Image task to copy image from golden master to server.
5. Use the Create Boot Diskette task to create a boot diskette to be used to replicate the clients. This step is not necessary if you are booting over the network (see “Booting over the Network”).
6. Insert the boot diskette into each client and reboot the system.
Add a client to the cluster or recover a client after a disk failure
1. Use the Configure Client List task to define the new client. (This step applies only to adding a client to a cluster.)
2. Insert the boot diskette into the client and reboot the system or boot over the network (see “Booting over the Network”).
Install or upgrade software, change configurations, or add or delete files or directories
1. Update the golden master.
2. Use the Prepare Image task to update the existing image or create a new one.
3. Use the Synchronize Clients task to update the clients with the new image.