8K is the ZFS default. And ZFS even warns you if you try to create a 4K volblocksize zvol and recommends to use at least 8K.But if Windows and Linux use 4k as the default cluster size, would it not be even better to set it to 4k default instead of the default 8k PVE uses currently? Or was that done by PVE because I use mirror?
Yeah, raidz1/2/3 is primarily useful as cold storage using datasets. When using zvols you usually also want the IOPS performance and low volblocksize you only get with (striped) mirrors.I have read about that padding problem and how it is hard to set is right with compression and how you are basically better of with mirror for zvols. But I am unable to find it right now. Maybe a strong encouragement for mirror in general would be good for PVE