Thanks for the suggestionOh. That kind of sounds like your ZFS storage doesn't have "Thin provision" enabled?
If you take a look at Datacenter → Storage → [storage pool], it should be a checkbox option in there:
View attachment 69420
Or are you thinking about LVM with thin provisioning for a different reason?![]()

I was thinking about LVM thin due to being told that ZFS mirrored would just always be slow with these cheapo SSD's I'm using (this is just a homelab thing with scavenged parts). Thought maybe LVM would be more suitable. I dont know ... maybe mirror is just not plausible for the home scenarios with normal PC hardware?