FreeBSD using swap even though there's a lot of free memory

[Michael Sierchio]

On Thu, Oct 15, 2020 at 7:24 AM Twingly Customer Support <team at twingly.com>
wrote:

> Hi,
>
> We have a server running FreeBSD 12.1-RELEASE-p10. We currently have a
> problem where FreeBSD starting to swap when running ZFS scrub, even though
> we have ~70G of free memory.


tl;dr – this is normal, nothing to see, move along.

It's not "swapping" – it's paging pre-emptively.  If you're used to Linux,
you might think "swap bad"  ;-)   There is a lot of history to VM
management in BSD.  This might be an easy place to start:

https://flylib.com/books/en/2.849.1.78/1/

-- 

"Well," Brahmā said, "even after ten thousand explanations, a fool is no
wiser, but an intelligent person requires only two thousand five hundred."

- The Mahābhārata