Computer Identification in CA ITCM Environment

Products

• CA Client Automation - IT Client Manager
• CA Client Automation
• CA Client Automation - Patch Manager
• CA Service Management - Service Desk Manager

Issue/Introduction

DSM/ITCM assigns each managed computer a CA-specific Universal Unique Identifier (HostUUID). This data is stored at the following locations on each computer:

Windows registry:

On a 32-bit OS: HKEY_LOCAL_MACHINE\SOFTWARE\ComputerAssociates\HostUUID
On a 64-bit OS: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\ComputerAssociates\HostUUID

Linux/UNIX:

/etc/cadmuuid

The CA ITCM application framework (CAF) checks the locations for a CA Technologies-specific UUID periodically. If a UUID is found, CAF assumes that this asset has already been registered in the database. If the UUID is not found, CAF creates a new UUID and registers the asset to the database.

If you have copied an installation (physical dump of the hard disk using an imaging tool such as GHOST or image file of a virtual machine using a tool such as VMware) to install on another computer or to use as a backup, the copied installation contains a CA-specific UUID of the original computer. If you start the copied installation on a computer other than the original one, the CA-specific UUID would appear twice.

Environment

Client Automation - All versions

Resolution

To prevent the duplication of CA-specific UUID, CA ITCM performs the following actions:

1. When CAF starts or when the "caf register" command is issued, an algorithm that verifies if the target computer is the original computer or another computer is executed.
2. If the target computer is the original computer, the original CA-specific UUID is used; else, a new CA-specific UUID is created. 
   
   To detect the need for a unique CA-specific UUID, CA ITCM can use either the default algorithm (recommended) or the legacy algorithm. The algorithm checks for the following characteristics of the target computer against the values in the database:

Virtual machine

System ID (a system BIOS attribute) is the only characteristic checked by the algorithm.

Physical computer

1. MAC address compliance 
   
   If one of the MAC addresses matches with one of the original MAC addresses of the target, this criterion is fulfilled. 
   
   
2. Hard disk serial number compliance 
   
   If one of the hard disk serial numbers matches with one of the original hard disk serial numbers of the target, this criterion is fulfilled. InfrastructureComponent Considerations 
   Chapter 2: Planning the Infrastructure Implementation 85 
   
   
3. System ID compliance 
   
   If the System ID matches with the original System ID of the target, this criterion is fulfilled.

 

A change in the values of the preceding characteristics does not necessarily require a change in the CA-specific UUID. The following are the considerations for the algorithm to initiate a change in the CA-specific UUID:

• A change in the value occurs only if the original value of the characteristic exists in the database and the new value is different from the original value.

For example, if the old list of MAC addresses is not available in the database for comparison, a change in the CA-specific UUID will not be initiated.

• A change in the value occurs only if the new values of MAC addresses or disk serial numbers match with the existing values in the database.

Lock Host UUID

A hardware change usually results in the change of the host UUID. If you do not want to change the host UUID, you can lock the host UUID.

• To lock the host UUID on Windows, you must create a string value LockHostUUID with value "1", under the registry key HKLM\Software\ComputerAssociates\HostUUID.
• To lock the host UUID on Linux or UNIX, create a file named /etc/calockuuid.

* Please note that "original" in the above context means the value recorded at the time the agent was installed.

If two of these three criteria are not met, the target system is regarded as being a new computer and a new HostUUID is generated.