AIX Maintenance Strategy

This document clarifies the AIX Maintenance Strategy by detailing fileset versions, Program Temporary Fix (PTF) and preventive maintenance packages. To ensure the integrity of installed software in the AIX operating system, a method is necessary to track and maintain updates to the system. This method is the Maintenance Strategy and can be summarized as "upward only."

The information in this document applies to all versions of AIX.

Related documentation

The product documentation library is also available at the following URL:
http://www.rs6000.ibm.com/resource/aix_resource/Pubs/index.html

Fileset

A collection of logically related files; the smallest installable or updatable unit in AIX.

VRMF

Version Release Maintenance Fix level; describes the level of a fileset.

PTF

Program Temporary Fix; a fileset update at a particular VRMF level. A temporary solution to, or bypass of, a defect in a current release of a licensed program.

The following chart shows the difference between a maintenance release and a PTF (corrective service). Each x represents a single fileset of AIX (such as bos.mp).

	   (1)		   (2)			   (3)	
VRMF	Base Install	Base Install +		Base Install +
			Maintenance Release	Maintenance Release +
						PTFs
432
						    x
						  x x
431			  xxxxxx  		  xxxxxx
			  xxxxxx		  xxxxxx
			  xxxxxx		  xxxxxx
430	xxxxxxxxxx	xxxxxxxxxx		xxxxxxxxxx
OSLEVEL	  4.3.0		  4.3.1			  4.3.1

Description

(1)Base Install

In this case, 4.3.0 media was installed with no maintenance or fixes applied.

(2)Base Install + Maintenance Release

This results from installing 4.3.1 media or by installing 4.3.0 media; and later applying changes from 4.3.1 media.

(3)Base Install + Maintenance Release + PTFs

This system probably had 4.3.1 maintenance release applied, with a few individual PTFs later applied to particular filesets. This is likely in response to a particular problem, or one user's environment matched that of another user who had a problem, and they are applying these fixes to prevent the same problem from occuring.

NOTE: Some filesets remain 4.3.0 because the fileset did not change as part of the 4.3.1 maintenance release.

"Recommended maintenance" is a set of PTFs applied on top of a maintenance release. While a maintenance release increases the third portion of the VRMF, the recommended maintenance does not. More specifically, recommended maintenance is a set of PTFs that have been tested together and have enough test or field experience to be recommended for preventive maintenance.

See the chart below:

	   (1)		   (2)		   (3)		   (4)
	AIX 4.3.1	AIX 4.3.2	AIX 4.3.1-01	AIX 4.3.1
							w/PTFs
432			  xxxxxxx 			         x
			  xxxxxxx	    xx   x	         x 
			  xxxxxxx	   xxxx  x	   xxxx  x
431	xxxxxxxxxx	xxxxxxxxxx	xxxxxxxxxxx	xxxxxxxxxxx

Description

(1)AIX 4.3.1

This is an AIX 4.3.1 setup with no fixes or recommended maintenance applied. This does have the 4.3.1 maintenance release rather than the 4.3.0 base AIX.

(2)AIX 4.3.2

This is an AIX 4.3.2 setup. Not all filesets need to change from 4.3.1; therefore, some filesets remain at 4.3.1, even though the system is fully updated to AIX 4.3.2 and the oslevel command will return 4.3.2.0.

(3)AIX 4.3.1-01

In this case, AIX 4.3.1 maintenance release is applied. The system has also applied "AIX 4.3.1-01 Recommended Maintenance." This exact set of applied fixes (or higher) is necessary to be considered to have this recommended maintenance applied.

(4)AIX 4.3.1 with PTFs

The recommended maintenance is not applied in (4). Notice that although many of the same filesets are applied, some of them are below that of the recommended maintenance pattern. Therefore, this system simply has PTFs applied to AIX 4.3.1 and does not have AIX 4310-01 installed. This is true, even though one fileset is even higher than that required by AIX 4310-01.

PTFs (Corrective Service) are applied to correct or prevent a particular problem. PTFs undergo testing for the particular problem they are designed to correct and regression testing to prevent introduction of new problems. However, PTFs are not tested as extensively as a maintenance release or recommended maintenance. PTFs should only be applied to correct or prevent a critical problem.

See the chart below:

	   (1)		   (2)		   (3)
	AIX 4.3.1	Desired Fix	Resulting System
432
			   x		   xx
			   x		  xxx
431	xxxxxxxxxx	xxxxxxxxxx	xxxxxxxxxx

Description

(1)AIX 4.3.1

Assume this is your current system.

(2)Desired Fix

Assume that you wish to update a single fileset to a higher level for the purpose of avoiding a problem described to you by support services.

(3)Resulting System

Keep in mind that the installed fix can require other filesets to be updated as well.

AIX installation architecture assumes that any fileset update with a higher VRMF level contains the updates from all previous updates to the same fileset. In order to prevent updates from being removed, an "upward only" strategy is used. Because AIX 4.3.2 is considered higher than any level of AIX 4.3.1, you cannot create a fix for AIX 4.3.1 that 4.3.2.0 does not already contain.

For example, bos.mp.4.3.2.0 contains defect X, which is corrected by installing 4.3.2.1. Later we find this same defect exist in bos.mp.4.3.1.12, which was highest at the time it was created. So, if we create a bos.mp.4.3.1.13 to correct this defect, a customer could at a later time install bos.mp.4.3.2.0 and reintroduce the defect. In addition, the system would insist that the fix for that defect is already installed.

Therefore, the upward only requirement necessitates that the fileset be taken to bos.mp.4.3.2.1. This could, however, require other filesets to be updated as well.

Typically, customers have two options for ordering fix packages. Each of these has advantages over the other, as detailed below.

• Latest updates

  Latest updates are simply the set of updates available for a given AIX release. Latest updates have been tested together, but they have not undergone the more extensive testing common to the maintenance release or recommended maintenance. For this reason these packages are not recommended as preventive maintenance. However, using this package will allow you to instantly apply a single PTF that support has informed you will correct the problem. Latest updates are best used to avoid long download times sometimes required for obtaining fixes.

• Recommended maintenance

  Recommended maintenance is a set of updates that have been tested together and have undergone sufficient field experience to be recommended as preventive maintenance to avoid problems and issues that could arise from defects. Keep in mind, however, recommended maintenance sets will not have every update that has been released. Use recommended maintenance sets as part of your ongoing preventive maintenance strategy.

To determine the maintenance release installed, enter the following command:

	oslevel

To determine which filesets need updating for the system to reach a specific maintenance release (in this example, 4.3.3.0), enter the following:

	oslevel -l 4.3.3.0

To determine if a recommended maintenance package is installed (in this example, 4.3.3.0-02), enter:

	instfix -ik 433-02_AIX_ML

To determine which filesets need updating for the system to reach the 4.3.3.0-02 level, enter:

	instfix -ciqk 4330-02_AIX_ML | grep ":-:"

IBM supports AIX base on the Version.Release. Therefore, the customer purchases support based on the Version.Release of AIX, not the maintenance level. For instance, if you have purchased AIX 4.3, you will receive support for all releases of AIX 4.3 (4.3.1, 4.3.2, 4.3.2 4.3.x, etc.).

NOTE: Updating from one Version.Release to another requires a new license and involves some cost.

Maintenance levels, recommended maintenance, and PTFs are free. You can obtain each of these electronically, at no charge, from ftp and web sites (see http://techsupport.services.ibm.com).

Fee based services (such as phone support), may charge for the convenience of their support, but the code itself is free. In many cases, the fees are monthly and do not attach additional costs for making multiple calls to support centers. Some locations, however, may charge for media if you request the code be sent to you on tape or CD.

[ Doc Ref: 9580572862128     Publish Date: Oct. 02, 2000     4FAX Ref: 8565 ]