On Sun, Mar 21, 2021 at 03:10:41PM +0000, ???????????? ?????????????? wrote:

What does it mean "Tor's file descriptor usage is at 90%. If you run out Tor will be unable to continue functioning."?

That sounds like a message from nyx: https://nyx.torproject.org/

It means that your "ulimit -n" is too low.

Typically the Tor package includes an init script that raises ulimit -n for you. For example: https://gitweb.torproject.org/debian/tor.git/tree/debian/tor.init#n40

So if you are not using a Tor package like the deb, now is the time to start.

--Roger