How to divide a huge catalog to save space on my internal drive.

[Danchu5]

I'm running LR classic.  I've been using one catalog for years which is in the internal drive.  The photos are in external drives.  My catalog is very big so its bogging up the internal drive.  I want to separate the catalog into "old" and "new" where the only "new" catalog runs from the internal drive (faster).  The "old" catalog can run from the external.  By doing this I can lighten up the internal drive, correct? Any ideas? Also, I see a folder called "corrupted catalog" I can safely delete this, yes?

[dj_paige]

My recommended solution: one catalog on a larger drive.

If not that, delete the previews of the "old" photos, keep one catalog.

Please explain "bogging up the internal drive" in more detail, exactly what happens?

[JohanElzenga]

Your catalog file will not be that big, it's the previews that take so much space. What you can do is delete 'Catalogname Previews.lrdata'. 
Lightroom Classic will rebuild this package, but it will only rebuild previews if and when needed. That means that it will not build previews for old photos that you never use and never look at, keeping the previews package much smaller than it is now. And yes, you can delete that 'corrupted catalog'. It is a left-over from some time ago when Lightroom needed to repair the catalog.