Lesson - 3 AIX 6.1 OS Installation and Software Management

AIX OS INSTALLATION 
 
Three kinds of OS installations available in AIX

1. New and Complete Overwrite
2. Migration
3. Preservation

1. New and Complete Overwrite:

     This is New installation; in this installation we have three options

A. Start installation with default settings.
        This is normal installation
B. Change/show installation settings and install
        In this installation we can change the installation disk (hdisk0, or hdisk1), Desktop options
C. Start maintenance mode for recovery
        This is used for recover the existing OS problems. (Boot image, Boot list, File systems problems).

2. Migration:

 
    In this migration Installation, Operating system Updated from
 lower level to higher level i.e AIX 5.3 to 6.1 

 NOTE:

     In this installation System data will not be affected except the /tmp file system. i.e. /tmp file system will be deleted and newly created.

3. Preservation:

 
    This installation is overwriting the existing OS and user data directory /home only persevered, rest of the directories /, /var, /tmp, /etc, /dev, /opt will be deleted and newly created. 

  NOTE:

     In this installation we can preserve additional directories also, suppose if you want preserve /opt, this case u should put /opt file system entry in /etc/preserve.list file.

FAQ

         When we select the preserve installation, only /home directory will be preserved,and /etc directory also will be deleted. Then how additionally preserved directories will not be deleted?

Answer:

         When we start the preservation installation, first installation will check ODM for /etc/preserve.list file, if any file system entry is found then it will preserve the file system i.e. What are the file system entries available in the /etc/preserve.list file, after that /etc file system also will be deleted and newly created.

SOFTWARE MANAGEMENT

         There are 4 types of software components, they are

                i) Filesets
               ii) Packages
              iii) LPP (Licensed Program Product)
              iv) Bundle

           The hierarchy of  above these are as follows

AIX Package Hierarchy

Fileset Naming conventions

 

Filesets:

• A fileset is the smallest individually installable unit in the LPP hierarchy. 
• A fileset includes all files that constitute a complete product such as “bos.net.uucp” or separately installable part of the product such as “bos.net.nfs.client” in the bos.net package. 
• It is available in the “backup file format”  (bff).   

Packages:

• A package is a group of separately installable fileset that provide a set of related function. 
• It is a single installable image. Ex., bos.net

Licensed Program Product (LPP)

• A LPP is a complete software  product collection including all packages and filesets as required. 
• For ex., BOS itself a LPP, which in turn the complete collection of packages and filesets. 
• Other Examples are devices, X11,rsct 

Bundles

• Are the list of softwares which contains LPP, packages and filesets, which are used for a specific use. Bundles are the actual software. 
• Ex; Server Bundle, Graphics Bundle , network bundle. 
• Bundles available may vary from configuration to configuration.
• Predefined system bundle in the AIX include
          AppDev, CDE, GNOME, KDE, Netscape, devices etc.
• Default bundles used for the system are in the /usr/sys/inst.data/sys_bundles.
• User created bundles are stored in /usr/sys/inst.data/user_bundles.

SOFTWARE UPGRADE

#oslevel (shows the actual BOS level)

6.1.0.0

V.R.M.F

   The numerical information that shows what level of software you currently have installed is broken into four parts. 

V -- Version

R -- Revision

M -- Modification

F -- Fix  

 

Note: 

      Filesets are divided by what part of the system they install to.This is either “root”, “usr” or “share” .

Types of upgrade

There are 2 types of upgrade available in AIX. 

1)  “Version and Release”  upgrades are normally called as Migration, which will be covered in the AIX Installation/upgradation part. Also these upgrades are purchased.

2)  “Modification and Fix”  upgrades are generally called as  TL/ML or SP or Fixes . These fixes are availabe at no charge.  Or downloaded from AIX site. 
        -  Using “smit update_all” command we can update fix or modification levels.
        -  These changes provides fixes to defects or additional  functions to  the BOS or optional software products.

SOFTWARE STATES

Software States

 There are 3 software states in AIX Package management

i) APPLIED - "can be rolled back"

• Provide oppurtunities to test the s/w. 
• Prevents the future re-installation of the product. 
• Enable to go back to previous version in case of any problem. 
• Enables to commit the s/w at the later stage. 
• Requires more disk space.  

ii) COMMITTED - “can't be rolled back”

• Requires less space.
• Permits to future installation. 
• Prevents from easily going  to the previous version.

iii) REJECTED 

        Reject removes the APPLIED software and go back to the previous committed version.  

PATCHING MANAGEMENT 

TL ( Technology Level earlier ML – Maintenance Level)

  

• A TL contains  new hardware and software features and service updates, all requisites are added to it. So that whole TL is intalled. 
• Released every Six months.
• TL is installed wholly not as partially . Need to backup the system prior to installing a TL.
• TL will be never rolled back.

SP ( Service Pack)

•  A  SP (Service Pack) consists of serivce-only updates ( also known as PTFs ) that are release between TL s to be grouped together for easier identification .                                                                       #/usr/lpp/bos/AIX_file_lis                                                                  #ls

U827841.bff  U827847.bff  U827854.bff  U827859.bff  U827864.bff  U828003.bff  U835283.bff  U827843.bff  U827848.bff  U827855.bff  U827860.bff  U827865.bff  U828006.bff  dlmgr.pro U827844.bff  U827849.bff  U827856.bff  U827861.bff  U828000.bff  U828007.bff U827845.bff  U827850.bff  U827857.bff  U827862.bff  U828001.bff  U828010.bff
U827846.bff  U827851.bff  U827858.bff  U827863.bff  U828002.bff  U828011.bff

• In simple words, An SP is a bundle of PTFs released between TLs. These fixes address highly pervasive, critical or security-related issues. SP are provided for  the N and N-1 release. 
• To check the SP use #oslevel -s  
• A group of "important fixes" delivered between Technology Levels. E.g. 5300-04-01 is AIX 5.3 ML 4 Service Pack 1.

 PTF ( Program Temporary Fix)

• “Program Temporary Fix” or Just a Patch  is an updated fileset or new fileset that fixes a system problem. 
• It can be installed using “installp” command. 
• In format of  “U476294” -- Uxxxxx .
• A PTF which has been applied to an AIX system (but not committed) can be rejected (backed out).

APAR (Authorized Program Analysis Report)

• APAR is  a number used to identify reported problems caused by a suspected defect in a program.  
• A fix to an APAR can be made up of one or more fileset updates.
• APARs are eventually become PTFs after testing and verification.
• APARs are directly applied to the system throughthe use of “instfix”  command . 
• For example, PTF U476294 fixes APARs IY18782, IY18936, IY19534, and IY19765

Note

     When tracking requirements and susceptibility, it is best to either track filesets, APARs or MLs. PTFs may not be tracked by LPP, and so are not useful.

 

Methods to  Upgrade TL
    i)  Normal Method (al_disk_install)
   ii) MultiBOS method
       This is by far the coolest way to have AIX upgraded. It was introduced with AIX 5.3 TL3. This is great in cases where only one disk is available on rootvg and no free disks for alternate disks are available.
iii) Restoring mksysb

Pre-requisites of  TL/SP upgrade    i) Check the current TL level.
   ii) Take the backup using mksysb (Multibos or alt_disk_install) .
   iii) Perform TL update activity.

   iv) Also, it is a good practice to create a health checklist, that is, save as much as information from the system (netstat, ifconfig, lsvg, lsdev, lscfg, prtconf, etc.) and keep it somewhere other than the server that is being upgraded.
    v)  Also, TL updates should always be committed because they cannot be rejected. If a TL has been applied and needs to go back to the previous version, then a fallback plan is needed.
   vi) With a TL or SP upgrade installp will automatically remove an interim fix only if the service pack already contains it. If not the upgrade will fail and you have to remove it with the efix manager before upgrading.