Clean install & Time Machine

[bp1000]

I have had my MBA since 2011 and i haven't re-installed OSX and now i would like to try a clean install.

Over the years HDD has been slowly filling up, i have a few issues like my fans go beserk and the laptop goes hot if i wake the laptop up on AC if it had previously slept on battery. Also my battery health is terrible.

These are probably all unrelated to the OS but i just fancy going back to a clean machine.

I only need a few apps and files everything else is cloud based.

However, i back my mba up to a generic external HDD with time machine.

I'm assuming i just boot to recovery and choose reinstall mountain lion.

What happens when i plug in my time machine drive, will it carry on backing up or will it overwrite my old backups?

Ideally i want to be able to reinstall osx and keep my old backups but continue using the same drive for time machine but on the new OS. That way, if i need to go back and restore from timemachine on the old backups i can.

I'd rather not partition the backup drive as i would have space constraints then.

Thanks

 

[benwiggy]

Yes, your problems are unrelated to the "state" of your OS, and reinstalling probably won't help, and if it does, there might be easier methods of effecting the same result.

After reinstalling, you can use the Migration Assistant to restore some or all of the backup -- settings, user data, apps.
There is an option to "inherit backup history" in MA.

 

[Krazy Bill]

There is an option to "inherit backup history" in MA.

Yes, but going to Massachusetts seems like overkill to me.