Instance is managed by using profiles. Profiles will resides in (usr/sap/<SID>/sys/profiles)
There are three types of Profiles
3. Instance Profile
As part of post installation we import the profiles of Active servers from RZ10.
The profiles resides at OS level in the directory (usrsap<SID>sysprofile). They can be managed/ edited using a notepad. But the consistency is not checked (say for eg. if we modify the instance profile WP DIA=2000 and there is no error message and versions are not maintained under OS level)
So these profiles are imported into database management for consistency check and version management.
Startup profile consists of startup parameters like
Starting Message Server
Dispatcher + Work.
Do not modify these parameter under any circumstances on OS level.
It is used to provide global parameters for all the instances, buffer parameters, security parameters (Password, User restrictions), Message server host, enqueue host)
This is specific to instance configuration such as work process, timeout parameters etc.
1. Startup profile is read by the system to start the engine by starting database, message server and dispatcher in Central Instance.
2. Startup profile is read by the system to start the engine by starting (DISP+WORK) on dialogue instance.
3. There will be only one default profile in the entire system which provides global values.
4. Instance specific profile - This is used to set the instance specific parameters.
Eg. How many profiles are available on a system with 10 Dialogue instances.
Total = 11 (including Central Instance)
11 X 2 per instance (Start + Instance)
22 + 1 (Default Instance) = 23