D Frequently Asked Questions

This appendix outlines frequently asked questions on provisioning Linux.

D.1 Frequently Asked Questions on Setting Up the Provisioning Environment

What is PXE (Pre-boot Execution Environment)?

The Pre-boot Execution Environment (PXE, aka Pre-Execution Environment) is an environment to bootstrap computers using a network interface card independently of available data storage devices (like hard disks) or installed operating systems. Refer to Appendix B for more information.

Can my Boot server and Stage server be located on different machine?

It is recommended that the Boot server and Stage server are co-located on the same physical machine. If this is not done, then one has to ensure that the network boot directory (say /tftpboot/pxelinux0.cfg) is exposed to Stage server via NFS and can be mounted by it.

Can my boot server reside on a subnet other than the one on which the bare metal boxes will be added?

Yes. But it is a recommended best practice to have boot server in the same subnet on which the bare metal boxes will be added. If the network is subdivided into multiple virtual networks, and there is a separate DHCP/PXE boot server in each network, the Assignment must specify the boot server on the same network as the designated hardware server.

If one wants to use a boot server in a remote subnet then one of the following should be done:

-- Router should be configured to forward DHCP traffic to a DHCP server on a remote subnet. This traffic is broadcast traffic and routers do not normally forward broadcast traffic unless configured to do so. A network router can be a hardware-based router, such as those manufactured by the Cisco Corporation or software-based such as Microsoft's Routing and Remote Access Services (RRAS). In either case, you need to configure the router to relay DHCP traffic to designated DHCP servers.

-- If routers cannot be used for DHCP/BOOTP relay, set up a DHCP/BOOTP relay agent on one machine in each subnet. The DHCP/BOOTP relay agent relays DHCP and BOOTP message traffic between the DHCP-enabled clients on the local network and a remote DHCP server located on another physical network by using the IP address of the remote DHCP server.

Why is Agent rpm staged on the Stage server?

Agent rpm is used for installing the Agent on the target machine after booting over network using PXE.

Can I use the Agent rpm for installing Agent on Stage and Boot Server?

This is true only if the operating system of the Stage or Boot Server machine is RedHat Linux 4.0, 3.1 or 3.0. Refer to section Using agent rpm for Oracle Management Agent Installation on the following page for more information:

http://www.oracle.com/technology/software/products/oem/htdocs/provisioning_agent.html

Can the yum repository be accessed by any protocol other than HTTP?

Though the rpm repository can be exposed via file:// or ftp:// as well, the recommended method is to expose it via http://. The latter is faster and more secure.

How to setup a reference host if I don't have an Oracle Enterprise Linux server?

In case one does not have an Oracle Enterprise Linux server then one can switch a RedHat Linux server to Oracle Enterprise Linux. To do this, follow the steps described here:

https://linux.oracle.com/switch.html

Create an Oracle Enterprise Linux server using installation media available at:

http://edelivery.oracle.com/linux

D.2 Frequently Asked Questions on Setting Up and Provisioning Default Images

Is it possible to include extra packages other than the one on reference machine?

This can be done by using the custom_rpms.properties file. This file can be found at:

<AGENT HOME Oracle Home on the Reference Machine>/agent10g/sysman/admin/scripts/provisioning/custom_rpms.properties

Modify the [additional rpms] section of this file to mention any additional rpms not present on the Reference Machine. Only the name of the package without the version should be mentioned. Refer to Appendix C.

Is it possible to exclude any packages from reference machine while provisioning the default image on the target machines?

To prevent any rpms present on the Reference Machine from being installed on the target machines, mention the list of rpms to be excluded in the [deny_rpms] section of the custom_rpms.properties file. Refer to Appendix C.

D.3 Frequently Asked Questions on Directives and Components

Are directives associated with Components or Images?

Directives can be associated with both components and images. As explained later during the creation of components and images, directives are actually associated with one of Staging, Pre-Install, Install or Post-Installation provisioning steps of a component. In case of an Image, directives can be associated with Stage, Cleanup, Post-Install, and Diagnostics provisioning steps of an Image.

What is the significance of the Status of a directive? How can one change it?

Look at the following table to know the possible Status values and what they signify.

Table D-1 Status Values

Status	Description
Incomplete	This Status signifies that some step was not completed during the directive creation, for example uploading the actual script for the directive, or a user saved the directive while creating it and still some steps need to be performed to make complete the directive creation.
Ready	his signifies that the directive creation was successful and the directive is now ready to be used along with any component/image.
Active	A user can manually change the status of a Ready directive to Active to signify that it is ready for provisioning. Clicking Activate changes the Status to Active.

What is a Maturity Level of a directive? How can one change it?

Look at the following table to know the possible Status values and what they signify:

Table D-2 Maturity Levels

Maturity Level	Maturity Level Description
Untested	This signifies that the directive has not been tested and is the default maturity level that is assigned to the directive when it is created.
Beta	A directive can be manually promoted to Beta using the Promote button after testing the directive.
Production	A directive can be manually promoted to Production using the Promote button after a user is satisfied that the directive can be used for actual provisioning on production systems.

Can a same component be used in multiple images?

Yes. Components are reusable and a given component can be a part of multiple images at the same time.

Do I need to modify the images associated with a component, if the component is edited?

No. If the component is changed for some reason then the change is propagated to all the images with contain that component.

For creating the Linux OS component does the Reference Machine need to have a management agent running on it?

Yes. Reference Machine has to be one of the managed targets of the Enterprise Manager.

What if the working directory does not have enough space while creating a clone component?

The component creation job that is kicked off in the end will indicate that the component creations failed because of insufficient space. Create the component again by specifying a temporary directory with sufficient space and the creation will succeed.

What is the significance of the Status of a component? How can one change it?

Status of a component is similar to that of a directive. Refer to What is the significance of the Status of a directive? How can one change it?.

What is a Maturity Level of a component? How can one change it?

Maturity Level of a component is similar to that of a directive. Refer to What is a Maturity Level of a directive? How can one change it?.

What is the purpose of associating Properties with Generic Components?

Properties are used to provide flexibility for customizing the components depending on need. The property values are fed to the directives, which then customize the installation depending upon the values.

D.4 Frequently Asked Questions on Network Profiles and Images

Can I use 10.1.x IP addresses for Private Network Configuration?

No. Because of a known limitation this type of addressing cannot be done for the private IPs of the cluster nodes.

What is Reset Timeout?

After the OS installation on a target machine, management agent is installed on it, which reports to OMS and makes the machine a managed target of the Enterprise Manager. The time duration between the start of OS provisioning to agent reporting back to OMS server is known is the Reset Timeout. This is used by the provisioning application for deciding it provisioning process has timed out. If the machine or network is slow then it is advisable to set a high reset value.