Originally posted by: Mohammed Farooqui

After installation of AIX 7.1 (default), there are the CAS, CIMS, and platform agent subsystems automatically started. 

What is the impact of these on the system, as earlier  (AIX 6.1) we had no such subsystems started. 

Would it be fine to stop them , if not using it. Will it effect any other processing on the system.

Originally posted by: Pave1

That is what I usually do to get rid of all that useless stuff which only occupies memory and appears there after nearly every single upgrade:
         rmitab cimservices
         rmitab cas_agent
         rmitab platform_agent
         stopsrc -s cimsys
         stopsrc -s cas_agent
         stopsrc -s platform_agent
 

It stops all (I hope) IBM director stuff

Cheers, Pavel

Originally posted by: j.gann

if you are not using systems director (I do not know any customer who does)

best practice to prevent the agents  from being installed in the first place is:

place this in the bosinst_data file used during initial install:

SYSTEM_MGMT_CLIENT_BUNDLE = no

bye
j.gann

Originally posted by: Mohammed Farooqui

Thank you for the input. I will follow this during the migration.   However Now I have a query that which method is better. 

Fresh installation of AIX 7.1 and along with this the Database and Application and then customize this OS for the DB and Application.

OR

A Migration from AIX 6.1 TL08 to AIX 7.1....  My management believe that a migration will carry all the junk from the Old OS and also carry files from old OS which are not needed in the new OS. 

I am trying many blogs , but unable to find the answer. Please can this forum help me

Originally posted by: Pave1

I am no wandering that you could not find clear an answer as there is no one :)

from your (admin) point is might be better migration as it usually requires less effort for you

from management, security etc point might be better clean install

there can be many others implications I cannot see as do not your env, business, priorities ... perhaps clean install could be even faster than migration in your env (?)

both scenarios will work and it is up to you (your management st the end) what is more important for you, to have relatively clean systems or save many of MD by installing, configuring etc.

Cheers, Pavel

Originally posted by: j.gann

have you got your applications engineered well?

i.e. do you have a  script or package or procedure that will provision all of your individual application's requirements on top of a freshly installed aix? (that being OS tunables, sys0 attributes, ulimits, lpps, environment variables, users, groups, etc pp)

if so. fresh install is fine. if not, how do you want to make sure that all those requirements are being met?

badly engineered application -> aix migration install.

regards

jgann

Originally posted by: Mohammed Farooqui

Well from the beginning, we had AIX 5.3 and this was the default installation. Nothing much changed on the kernel settings. However only changes to user level environment variables as per oracle and application recommendation. 

When we moved to AIX 6.1, we performed a migration installation. And from then on we have not made any changes to kernel tunables. However I do agree there have been tweeks on the DB and application ends and most of which are not documented as well. 

Can anyone help me findout will the performance of the system be same after migration or fresh installation of AIX OS. I believe it will be the same. But I need an expert advice on this.