Reimaging Linux Systems

Linux configuration options

For the reimaging process, a configuration file is used at deployment time for both reimaging modes. The default configuration file is displayed in the corresponding field of the Deploy Image to Computer dialog. This file includes a base system configuration for the installation of the most common packages, and, for the install mode only, a standard partition layout.

The configuration file is updated on the target system during the reimaging task to copy the machine identity on the destination image. The language, keyboard, timezone, and network settings are added at run time for this purpose. To override this behavior, edit the configuration file by providing your values for these settings. The values you provide are used on the target instead of the default ones.

For more information about customizing the configuration files for the supported Linux operating systems, refer to the specific Linux vendor documentation. For example, you can view information about the RedHat Enterprise Linux Kickstart configuration file options for Version 6, at this link: https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Installation_Guide/ch-kickstart2.html, and information about the SUSE Linux Enterprise Server Control file for Version 11 SP3, at this link: http://doc.opensuse.org/projects/autoyast/index.html.

Valid reimaging combinations

To upgrade to SLE15, you must edit the configuration file of the reimage template correctly by selecting all the required modules and repositories. On a running SLE15 target, a list of modules can be found in /etc/zypp/repos.d. But this does not include packages installed after OS installation.

As a guideline, the configuration file reports a commented list of all available modules. BaseSystem Module is uncommented, as it is required. You must uncomment the other modules, as required for your system.

Reimaging in Upgrade mode

In the Deploy Image to Computer dialog, select Upgrade.

This mode is intended for upgrading to later service packs for the same major release. However, if you check Force upgrade the upgrade to a major release is forced, which could lead to an unsuccessful deployment. If you plan to change major release, you should use the install mode.

There are no required parameters for the Upgrade mode. Optionally, you can select to upgrade the BigFix client, by checking the corresponding option. You are then prompted to select the client package version. All selections that you make must be saved to a template. You can save to the Default template, choose to save your selections to a new template, or populate the dialog with settings from a previously saved template. The default configuration parameters that are stored in the installer response file and used for the upgrade are displayed. You can modify these parameters to suit your reimaging needs. Optionally, you can specify additional kernel parameters that the Linux installer uses during installation, and any client settings for the targets.

Reimaging in Install mode

In the Deploy Image to Computer dialog, select Install .

Select a previously saved template, create a new template to save the current settings, or save your selections to the Default template. When you reimage in Install mode, the BigFix client is installed. The default version is the same version as the BigFix server. You can select a different version by expanding Client Version. You must specify the root password of the target, or select a previously saved template that contains the correct root password.

The default deployment configuration parameters stored in the installer response file and used for the installation are displayed. You can modify these parameters to suit your reimaging needs. Optionally, you can specify additional kernel parameters that the Linux installer uses during installation, and any client settings for the targets.

Using the Linux System Reimage task

You can reimage Linux targets using the Linux System Reimage task. Select the image and the associated configuration template containing the settings to be used for the reimaging process that you have previously created and saved in the Image Library. Specify the root password for the target system if you are reimaging in Install mode. The password that you specify can be either in clear text or encrypted. In either case, the password is always encrypted during the deployment process.

You can optionally specify boot-time kernel parameters for the installer, and client settings.

For reimaging to run successfully on the selected targets, the Image Provider component must be running on the relays to which these targets are connected.

During task execution, the Linux installer boot files are saved in /boot/OSD_XX (if the target is BIOS) or /boot/efi/OSD_XX (if the target is UEFI), where XX is a randomly generated number.

During the final steps of the task, the original boot loader sequence is modified to start the Linux installer after the target reboots. The original boot loader configuration file is saved in /tmp/BOOTLOADER.rbobkp, where BOOTLOADER is either grub.conf or elilo.conf, depending on the boot loader on the target.

Password encryption

The root password that you supply for reimaging can be either in clear text or encrypted using any of the encryption methods supported by the corresponding Linux installers.

$id$mysalt$mypassword

Example 1:

# openssl passwd -1 -salt my_key
Password: mypassword

$1$my_key$jVY4Txf5wMoEsJX3ieQaR0

Example 2:

# python -c 'import crypt; print crypt.crypt("mypassword", "$6$my_key")'

$6$my_key$2Wz7.0skHT/FQI3yy9TbjPtLjjRq9cmU.TjnPGHWu4WUjemTR/
.TdaK68y2E63cxdxVaD58i64dyQIpnabUjz/

Changing Firewall settings