7.4. Systems

This page is not accessible from any of the standard navigation bars. However, clicking on the name of a system anywhere in the web interface brings you to this page. The default tab displayed on this page is the Details ⇒ Overview subtab. Other tabs are available, depending on the current entitlement level of the system.

rhnreg_ks --server=<server-url> --activationkey=<reactivation-key>,<activationkey> --force

This tab and its accompanying subtabs allow you to manage the software of the system: errata, packages and package profiles, and software channel memberships.

This tab and its subtabs, which do not appear without a Provisioning entitlement, assist in managing the configuration files associated with the system. These configuration files may be managed solely for the current system, or may be distributed widely via a Configuration Channel. The following section describe these and other available options on the System Details ⇒ Configuration subtabs.

This section is available to normal users with access to systems that have configuration management enabled. Like software channels, configuration channels store files to be installed on systems. While software updates are provided by RHN, configuration files are managed solely by you. Also unlike software packages, various versions of configuration files may prove useful to a system at any given time. Remember, only the latest version can be deployed.

This tab and its subtabs allow you to schedule and monitor kickstarts and to return your system to a previous state. Kickstart is a Red Hat utility that allows you to automate the reinstallation of a system. Snapshots keep a record of every change to a Provisioning system and allow you to "undo" those changes at will. Both features are described in the sections that follow.

IPADDR=192.168.0.28
GATEWAY=192.168.0.1

network --bootproto=static --device=eth0 --onboot=on --ip=$IPADDR
--gateway=$GATEWAY

This is tab allows you to create a new virtual guest on a host system or allows you to change the status of virtual guests.

The Virtualization tab has two subtabs, Details and Kickstart. These tabs appear the same for both virtual hosts and guests, but the functionality only makes sense for virtual hosts. It is not possible to create a guest system that runs on another guest system.

Provides the group name and group description. To change this information, click Edit Group Properties, make your changes in the appropriate fields, and click the Modify Details button.

Lists systems that are members of the system group. Clicking links within the table takes you to corresponding tabs within the System Details page for the associated system. To remove systems from the group, select the appropriate checkboxes and click the Remove from group button on the bottom of the page. Clicking it does not delete systems from RHN entirely. This is done through the System Set Manager or System Details pages. Refer to Section 7.4.4, “System Set Manager — ” or Section 7.4.2.9, “System Details”, respectively.

Target Systems — Lists all systems in your organization. This tab enables you to add systems to the specified system group. Select the systems using the checkboxes to the left and click the Add Systems button on the bottom right-hand corner of the page.

List of relevant Errata for systems in the system group. Clicking the Advisory takes you to the Details tab of the Errata Details page. (Refer to Section 7.5.2.2, “Errata Details” for more information.) Clicking the Affected Systems number lists all of the systems addressed by the Errata. To apply the Errata Updates in this list, select the systems and click the Apply Errata button.

List of all organization users that have the ability to manage the system group. Satellite Administrators are clearly identified. System Group Administrators are marked with an asterisk (*). To change the system group's users, select and unselect the appropriate checkboxes and click the Update button.

List all probes assigned to systems in the system group. The State shows the status of the probe. Click the individual System for details on the probe and to make changes to the probe configuration. Click the Probe to generate a customizable report on the monitoring.

A list of all the packages installed on the selected systems that might be upgraded. Systems must be subscribed to a channel providing the package for the system to be able to upgrade the package. If multiple versions of a package appear, note that only the latest version available to each system is upgraded on that system. Select the packages to be upgraded, then click the Upgrade Packages button.

A list of channels from which you may retrieve packages. This list includes all channels to which systems in the set are subscribed; a package is installed on a system only if the system is subscribed to the channel from which the package originates. Click on the channel name and select the packages from the list. Then click the Install Packages button.

A list of all the packages installed on the selected systems that might be removed. Multiple versions appear if systems in the System Set Manager have more than one version installed. Select the packages to be deleted, then click the Remove Packages button.

To subscribe or unsubscribe the selected systems in any of the channels, toggle the appropriate checkboxes and click the Alter Subscriptions button. Keep in mind that subscribing to a channel uses a channel entitlement for each system in the selected group. If too few entitlements are available, some systems fail to subscribe. Systems must subscribe to a base channel before subscribing to a child channel.

Use this subtab to distribute configuration files from your central repository on RHN to each of the selected systems. The table lists the configuration files associated with any of the selected systems. Clicking its system count displays the systems already subscribed to the file.

To subscribe the selected systems to the available configuration files, select the checkbox for each desired file. When done, click Deploy Configuration and schedule the action. Note that the files deployed are of the latest version at the time of scheduling and do not account for versions that may appear before the action takes place.

Use this subtab to validate configuration files on the selected systems against copies in your central repository on RHN. The table lists the configuration files associated with any of the selected systems. Clicking its system count displays the systems already subscribed to the file.

To compare the configuration files deployed on the systems with those in RHN, select the checkbox for each file to be validated. Then click Analyze Differences and schedule the action. Note that the files compared are of the latest version at the time of scheduling and do not account for versions that may appear before the action takes place. Find the results within the main Schedule category or within the System Details ⇒ Events tab.

Subscribe systems to configuration channels according to order of preference. This tab is available only to Satellite Administrators and Configuration Administrators. Enter a number in the Rank column to subscribe to a channel. Channels are accessed in the order of their rank, starting from the number 1. Channels not assigned a numeric value are not associated with the selected systems. Your local configuration channel always overrides all other channels. Once you have established the rank of the config channels, you must decide how they are applied to the selected systems.

The three buttons below the channels reflect your options. Clicking Subscribe with Highest Priority places all the ranked channels before any other channels to which the selected systems are currently subscribed. Clicking Subscribe With Lowest Priority places the ranked channels after those channels to which the selected systems are currently subscribed. Clicking Replace Existing Subscriptions removes any existing association and starts cleanly with the ranked channels, leaving every system with the same config channels in the same order.

In the first two cases, if any of the newly ranked config channels is already in a system's existing config channel list, the duplicate channel is removed and replaced according to the new rank, effectively reordering the system's existing channels. When such conflicts exist, you are presented with a confirmation page to ensure the intended action is correct. When the change has taken place, a message appears at the top of the page indicating the update was successful.

Administrators may unsubscribe from configuration channels by clicking the checkbox by the name of the channel and clicking Unsubscribe Systems button.

Administrators may enable configuration channel management by clicking the checkbox by the name of the channel and clicking Enable RHN Configuration Management button. You can also schedule the action by clicking the Schedule package installs for no sooner than radio button and using the drop-down menus to configure date and time, then clicking Enable RHN Configuration Management.

Use this subtab to re-install Red Hat Enterprise Linux on the selected Provisioning-entitled systems. To schedule kickstarts for these systems, select a distribution, identify the type (IP address or manual), and click Continue. Finish choosing from the options available on the subsequent screen. If any of the systems connect to RHN via a RHN Proxy Server, choose either the Preserve Existing Configuration radio button or the Use RHN Proxy radio button. If you choose to kickstart through a RHN Proxy Server, select from the available Proxies listed in the drop-down box beside the Use RHN Proxy radio button. All of the selected systems will kickstart through the selected Proxy. Click the Schedule Kickstart button to confirm your selections. When the kickstarts for the selected systems are successfully scheduled, the web interface returns you to the System Set Manager page.

Use this subtab to add meaningful descriptions to the most recent snapshots of your selected systems. To tag the most recent system snapshots, enter a descriptive term in the Tag name field and click the Tag Current Snapshots button.

Use this subtab to rollback selected Provisioning-entitled systems to previous snapshots marked with a tag. Click the name of the tag, verify the systems to be reverted, and click the Rollback Systems button.

Use this subtab to issue remote commands on selected Provisioning-entitled systems. First create a run file on the client systems to allow this function to operate. Refer to the description of the Configuration subtab of the Channels tab for instructions. You may then identify a specific user, group, timeout period, and the script on this page. Select a date and time to perform the command, and click Schedule Remote Command.

Click Update Hardware Profile followed by the Confirm Refresh button to schedule a hardware profile update. Clicking Update Package Profile,followed by the Confirm Refresh button schedules a package profile update.

Click Set a custom value for selected systems followed by the name of a key to allow you to provide values for all selected systems. Enter the information and click the Set Values button. Click Remove a custom value from selected systems followed by the name of a key to allow you to remove values for all selected systems. Click the Remove Values button to finalize the deletion.

Select the appropriate systems and click the Reboot Systems link to set those systems for reboot. To immediately cancel this action, click the list of systems link that appears within the confirmation message at the top of the page, select the systems, and click Unschedule Action.

Select the appropriate systems and click the Lock Systems link to prevent the scheduling of any action through RHN that affects the selected systems. This can be reversed by clicking the Unlock Systems link.

Click Delete System Profiles, then click the Confirm Deletions button to remove the selected profiles permanently.

Select, via the radio button, whether to Add, Remove, or make No Change in the entitlements of the selected systems. Click the Change Entitlements button to confirm your selection.

Toggle the Yes and No radio buttons and click the Change Preferences button to alter your notification preferences for the selected systems. You may apply these preferences to individual systems through the Properties subtab of the System Details page. Refer to Section 7.4.2.9.1.2, “System Details ⇒ Details ⇒ Properties” for instructions.

When a machine is to receive a network-based kickstart, the following events must occur in this order:

Although Red Hat Network has taken great pains to ease the provisioning of systems, some preparation is still required for your infrastructure to handle kickstarts. For instance, before creating kickstart profiles, you may consider:

While you can schedule a registered system to be kickstarted to a new operating system and package profile, it is also useful to be able to kickstart a system that is not registered with RHN, or does not yet have an operating system installed. One common method of doing this is to create a bootable CD-ROM that is inserted into the target system. When the system is rebooted, it boots from the CD-ROM, loads the kickstart configuration from the RHN Servers or your Satellite, and proceeds to install Red Hat Enterprise Linux according to the kickstart profile you have created.

To do this, copy the contents of /isolinux from the first CD-ROM of the target distribution. Then edit the isolinux.cfg file to default to 'ks'. Change the 'ks' section to the following template:

label ks 
kernel vmlinuz 
   append text ks={url} initrd=initrd.img lang= devfs=nomount ramdisk_size=16438 \
   {ksdevice}

IP addressed-based kickstart URLs will look something like this:

 http://my.sat.server/kickstart/ks/mode/ip_range 

The kickstart distribution selected by the IP range should match the distribution from which you are building, or errors will occur. {ksdevice} is optional, but looks like:

 ksdevice=eth0 

It is possible to change the distribution for a kickstart profile within a family, such as Red Hat Enterprise Linux AS 4 to Red Hat Enterprise Linux ES 4, by specifying the new distribution label. Note that you cannot move between versions (2.1 to 3) or between updates (U1 to U2).

Next, you may customize isolinux.cfg further for your needs, such as by adding multiple kickstart options, different boot messages, shorter timeout periods, etc.

Next, create the ISO as described in the Making an Installation Boot CD-ROM section of the Red Hat Enterprise Linux 3 Installation Guide. Alternatively, issue the command:

mkisofs -o file.iso -b isolinux.bin -c boot.cat -no-emul-boot -boot-load-size 4 \ 
-boot-info-table -R -J -v -T isolinux/

Note that isolinux/ is the relative path to the directory containing the isolinux files from the distribution CD, while file.iso is the output ISO file, which is placed into the current directory.

You may then burn the ISO to CD-ROM. To use the disc (assuming you left the label for the kickstart boot as 'ks'), boot the system and type "ks" at the prompt. When you press Enter, the kickstart should begin.

In addition to CD-ROM-based installs, RHN supports kickstarts through a Pre-Boot Execution Environment (PXE). This is less error-prone than CDs, enables kickstarting from bare metal, and integrates with existing PXE/DHCP environments.

To use this method, make sure your systems have network interface cards (NIC) that support PXE, install and configure a PXE server, ensure DHCP is running, and then place the appropriate files on an HTTP server for deployment. Once the kickstart profile has been created, use the URL from the Kickstart Details page, as for CD-ROM-based installs.

To obtain specific instructions for conducting PXE kickstarts, refer to the PXE Network Installations chapter of the Red Hat Enterprise Linux 4 System Administration Guide.

The following sections describe the kickstart options available from the Systems ⇒ Kickstart page.

The figure above shows the sub-tabs that are available from the Kickstart Details tab.

From the Kickstart Details ⇒ Details sub-tab, you can:

From this page, you can make the following changes to the operating system that the kickstart profile installs:

Kickstart variables can be used to substitute values into kickstart profiles. To define a variable, create a name-value pair (name/value) in the text box.

For example, if you wanted to kickstart a system that joins the network for specified department (for example the Engineering organization) you can create a profile variable to set the ip address and the gateway server address to a variable that any system using that profile will use. Add the following line to the Variables text box.

IPADDR=192.168.0.28
GATEWAY=192.168.0.1

To use the profile variable, you can use the name of the variable within the profile to substitute in the value. For example, the network portion of a kickstart file looks like the following:

network --bootproto=static --device=eth0 --onboot=on --ip=$IPADDR --gateway=$GATEWAY

The $IPADDR will be 192.168.0.28, and the $GATEWAY will be 192.168.0.1

Using variables are just one part of the larger Cobbler infrastructure for creating templates that can be shared between multiple profiles and systems. For more information about Cobbler and kickstart templates, refer to Chapter 11, Cobbler.

From this page, you can toggle several installation options on and off by checking and unchecking the boxes to the left of the option. For most installations, the default options are correct. The Red Hat Enterprise Linux System Administration Guide discusses each of these options in detail.

This sub-tab provides the information necessary to kickstart systems that are not currently registered with RHN. Using the on-screen instructions, you may either kickstart systems using boot media (CD-ROM) or by IP address.

The figure above shows the sub-tabs that are available from the System Details tab.

From the System Details ⇒ Details sub-tab, you can:

From this sub-tab, you can change the timezone associated with kickstarted systems.

From this sub-tab, you can indicate the partitions that you wish to be created during installation. For example:

partition /boot --fstype=ext3 --size=200 
partition swap --size=2000 
partition pv.01 --size=1000 --grow 
volgroup myvg pv.01 logvol / --vgname=myvg --name=rootvol --size=1000 --grow

If you have previously created a file preservation list, you may include that list as part of the kickstart. This will prevent the files in that list from being over-written during the installation process. Refer to Section 7.4.9.7, “Kickstart ⇒ File Preservation — ” for information on how to create a file preservation list.

From this sub-tab, select the GPG keys and/or SSL certificates to be imported to the kickstarted system during the %post section of the kickstart. For Satellite customers, this list includes the SSL Certificate used during the installation of the Satellite.

From this sub-tab, you can change information that may help with troubleshooting hardware problems:

The figure above shows the sub-tabs that are available from the Software tab.

Enter the package groups, such at @office or @admin-tools you would like to install on the kickstarted system in the large text box on this page. If you would like to know what package groups are available, and what packages they contain, refer to the RedHat/base/ file of your kickstart tree. Satellite customers will most likely locate this file here: /var/www/satellite/rhn/kickstart/<kickstart label>/RedHat/base/comps.xml.

If you have previously created a Package Profile from one of your registered systems, you can use that profile as a template for the files to be installed on a kickstarted system. Refer to Section 7.4.2.9.2.2, “System Details ⇒ Software ⇒ Packages” for more information about package profiles.

The Activation Keys tab, which has no sub-tabs, allows you select Activation Keys to include as part of the kickstart profile. These keys, which must have been created previous to creating the kickstart profile, will be used when re-registering kickstarted systems.

The Scripts tab, which has no sub-tabs, is where %pre and %post scripts are created. This page lists any scripts that have already been created for this kickstart profile. To create a new kickstart script:

 %include /tmp/part-include 

The Kickstart File tab, which has no sub-tabs, allows you to view or download the kickstart profile that has been generated from the options chosen in the previous tabs.

Kickstart variables can be used to substitute values into kickstart profiles. To define a variable, create a name-value pair (name/value) in the text box.

For example, if you wanted to kickstart a system that joins the network for specified department (for example the Engineering organization) you can create a profile variable to set the ip address and the gateway server address to a variable that any system using that profile will use. Add the following line to the Variables text box.

IPADDR=192.168.0.28
GATEWAY=192.168.0.1

To use the distribution variable, you can use the name of the variable within the profile to substitute in the value. For example, the network portion of a kickstart file looks like the following:

network --bootproto=static --device=eth0 --onboot=on --ip=$IPADDR --gateway=$GATEWAY

The $IPADDR will be 192.168.0.28, and the $GATEWAY will be 192.168.0.1

Using variables are just one part of the larger Cobbler infrastructure for creating templates that can be shared between multiple profiles and systems. For more information about Cobbler and kickstart templates, refer to Chapter 11, Cobbler.