I think you have a bit of a strange setup. You have a SAN without mirroring and not enough space to store a backup?
To clarify, I am not a system admin, but a DBA. Also SAN setup was put in before my time, so I cannot really comment on it. Backups are done via a software and then transferred to a NAS drive.
There seems to be no clear picture about your actual recovery needs, available resources and lack of experience
There is currently a software that does the windows backup, but it does not have the capability of doing Linux backup, hence I was requested to see if a scripting option is possible. The management has not defined any SLAs / recovery time, so I am trying to come up with possible options. I have to play with the resources and tools that are available, and if based on that, I am asking a question, does it qualify as lack of experience?
Where are you actually planning to store your backup? What is your file system layout? What is your required recovery window?
Backups will be done on the server and transferred to NAS drive. Standard linux file system layout on a datastore. Required recovery window is not specified, so I am working on a maximum 1 day period. All this was already planned, and was not dependent on the response of my original question.
You are apparently trying to implement a sophisticated backup strategy, but want to make it as general as possible. I think you are over-engineering the task
I intend to backup specific folders and in case of restore, re-install the OS, restore the important files, reinstall Oracle DB and restore via RMAN. I believe this is a standard backup strategy, and does not have any sophistication.
Sorry I did not mean to offend you and put you in any defensive position, but for some reason you keep coming back with the same questions and backup proposal. You cannot query for information how to create a professional backup strategy without providing detailed information about your recovery requirements, available resources, system layout and services used. How can anyone answer a question about what files or folders need to be in your backup procedure without knowing what data you need to recover?
Why are you so fixed on backing up folders? The suggestion that a complete system is usually not necessary does not mean you should backup folders instead. However, since you obviously don't know what you need to recover or how, you should backup the complete system. Whether this is feasible in your situation, no one will now because nobody can guess your recovery requirements and resources available.
If folders is what you want to do, you already received some good information. Whether or not the files you need are there is something you will have to check.