[seppel]

> Given that the author works at a large company, that has millions of machines, and where any swap change has cost implications in the tens of millions pounds, I suspect the article is based on data, rather than vibes.

Yes, but the author is most likely optimizing for a metric that I don't care so much in my per personal computer while dismissing metrics that I care about.

> It was always the case. but then a TB of disk isn't that expensive anymore.

But swapping out GB of RAM is expensive in terms of latency.

[KaiserPro]

but its rarely gb at the same time. Thats the point. Its a dumping ground for stuff thats not used very often. meaning that you can have a bigger VFS cache, which reduces latency

[seppel]

> but its rarely gb at the same time. Thats the point. Its a dumping ground for stuff thats not used very often.

But it has to be GB to actually make a difference. If your swap is not full of GB of data, then obviously you don't need it (or it just becomes a reserve when you are in an OOM situation - but this is where you don't want to be with swap avaible either)

[zygentoma]

> > but its rarely gb at the same time. Thats the point. Its a dumping ground for stuff thats not used very often.

> But it has to be GB to actually make a difference. If your swap is not full of GB of data, then obviously you don't need it (or it just becomes a reserve when you are in an OOM situation - but this is where you don't want to be with swap avaible either)

I think the parent meant, that it barely needs to be read / write GBs at the same time. Not that that much swap is never being in use at the same time.

So you can use a lot of swap, but will never need to read it back in all at once.

[KaiserPro]

indeed, thank you for explaining it clearer than me!