It works quite well too. As I understand it, SQLServer itself is effectively running on top of its own "OS" like layer (even on windows), so porting cleanly was made significantly easier.
Seconded. SQL server does work quite well on Linux and was surprisingly easy to get going. I prefer Postgres but sometimes we don't always get what what we want and hey, I'll take it cause I can use it on Linux!
As for MS Windows, WTF? Not only the forced ads making it seem like in some kind of casino built for 4 year olds (assume it's some kind of play to suck the kiddies in?), it's an abortion of mismatched UI, half of it trying to look like a cheaply built web app, then on next screen dumping you back into some NT style select panel. It's just awful. To say nothing of invasive updates and general Windows unpleasantness. I can say without reservation I have no use for the OS at all, Linux is just so much more pleasant to use at this point.
Is there any advantage to running it on Linux (except maybe the cost of a Windows license which is probably trivial compared to the cost of Sql Server itself)
I haven't seen benchmarks but I would guess that there isn't going to be much of a performance difference. It's like comparing the performance of your VM on different hypervisors, unless something is very wrong you won't see much difference.
As the OP indicated, MS SQL has it's own facilities for managing memory and disk I/O. It basically asks for all the resources from the OS and then does everything itself internally. I'm exaggerating obviously but it does try to avoid costly calls to the OS whenever and however possible which is why it was so easily ported to Linux.
The Docker images are smaller for Linux for one. Our team use the Linux version in tests during builds just for that. We are relying that Microsoft manage to keep the two versions close enough that it's meaningful.
