Recently We have migrated our DB servers in (OPS) from OS 4.0 to 5.1A (CFS) TRU 64 unix. We are planning to Convert our application servers
to change the OS version ( i..e 4.0 to 5.1A).

What are all steps to be followed before migration and after migration of our Application servers.

Present OS version of DB servers - 5.1A
OS version of APPS servers- 4.0

Application version - 11i (11.5.3)
DB version -