Filesystems or block devices that can be cached on other devices?

Question

linux

The question is mainly about Linux systems.
Whether technologies are currently available to cache a block device or file system on another block device or file system.
A classic example is a raid array of hard drives that periodically cannot cope with the load (for reading). I would like to install an intermediate SSD disk, on which the most frequently requested data would be automatically cached, and returned quickly from it, and if not on it, they were requested from slower devices.

Answer 1

Solaris ZFS - read about ARC architecture

Answer 2

It’s easier to implement such things yourself with a software layer (there is such a feature in nginx, you don’t even need to write anything yourself), and many raid controllers, say from Adaptec, already know how to do this.
On what task is your raid failing and what kind of raid do you have?

Answer 3

I want a universal solution. I know that such things are in big standalone stores.
It can be an example of a controller or a feature name, I have not yet seen such.
I have a variety of raids, from home trash to individual machines with dozens of disks distributing moons via fc/iscsi.

Answer 4

why do you want to cache on disk and not in RAM?

Answer 5

Also www.zfsbuild.com/2010/04/15/explanation-of-arc-and-l2arc/