Darwin had bunch of schedulers except this one: dualq, multiq, etc

In fact here's the one used in Sonoma: sysctl kern.sched -> edge

which seems to be an extension over "clutch":

https://github.com/apple-oss-distributions/xnu/blob/main/osf...

"… Single-cluster, symmetric (SMP) systems can run with just the Clutch policy, but multi-cluster, asymmetric (AMP) systems must further enable the Edge policy extension to Clutch in order to manage scheduling across the multiple CPU clusters. …"

Edge is also described in the linked document.

I meant "primarily this copies mechanism is targeted towards multiple devices setup".

With a single SSD it's indeed prone to the caveat which was pointed out; even if not due to being mapped to same storage "area" but also because SSDs often fail completely.

Also makes sense to note that __when__ narrowed to a single-disk setup ZFS' can be interchanged with Btrfs; almost same set of features but lesser overhead and complexity.

Wrong. ZFS' copies are made across several different devices.

(2nd copy)

If you are using ZFS on a single drive, they reside on the same drive by necessity. Which was the case the parent posters were talking about.