About btrfs with compression in Qubes OS

[rustybird]

Not sure, but I’ve replied in your other thread:

Any suggestions on mixing ssd and hdd in btrfs

You could similarly create an independent Btrfs filesystem on the SSD (or rather, on a new LUKS device on the SSD), set it up to be automounted, and add another file-reflink Qubes OS storage pool somewhere on the mountpoint. +1 This is just a guess but maybe Btrfs would decide based on whatever happens to be the PID of (one of) the kernel thread(s) servicing that particular xen-blkback device?