Hi Ajay,
whether it is supported to move only the SAP Abap dialog instance to run on Linux but the DB2 database and SAP Central instance remains on AIX. We have read notes 1067221 & 531069 which not though clearly but state that it is possible.
Yes, it is possible and there are many threads on this too.
Here are few examples, perhaps requested by customers so SAP has created these notes.
Refer: 1148109 - Heterogeneous Inst.(Appl. Server Windows, DB Unix)
1067221 - Composite SAP Note for heterogeneous installation
2) Beside what will happen to /sapmnt/<SID>/exe global mount which has AIX kernel & not directory like rs6000_64 & then kernel beneath. Because when we install the new app server on Linux it will ask for global /sapmnt mount point. Will it automatically move AIX kernel to rs6000_64 & create another directory linuxx86_64.
You cannot run AIX kernel on Linux, so adjustment are necessary for current and future updates.
Have a look at below note to understand it's possibilities.
Refer:
680617 - INST: Appl. Server in Heterogeneous SAP System Environment
Divyanshu