> Also keep in mind that an advanced format HDD sector is 4096 bytes. I haven't heard of any drives with more than ~4096 bytes per sector. There are some NVMEs

> Also keep in mind that an advanced format HDD sector is 4096 bytes. I haven't heard of any drives with more than ~4096 bytes per sector. There are some NVMEs which are 8192. Not sure which, because, we haven't learned a damn thing in ~15 years. I distinctly remember back in the 2000s Adaptec giving Theo at OpenBSD a run-around about driver code because they had lawyers in their ear trying to convince them that they should be patent and licensing trolls rather than hardware vendors (worked great for Lucent) and finally, in retaliation, he shipped a version of OpenBSD without Adaptec RAID support. https://openzfs.org/wiki/Performance_tuning#Alignment_Shift_.28ashift.29 https://openzfs.org/wiki/Performance_tuning#Alignment_Shift_... Why is this relevant? Because some of these NVME drives report wrong values for their sector size, so we're still in that same boat of being flat out lied to by the people we buy this hardware from. Some NVME SSDs, per testing, report 4096 when they're actually 8192. So you don't know what value to use until you set up a pool/dataset, test it for performance, and then if the performance seems off versus say... Anandtech benchmarks, destroy the pool/dataset and try the other value (this becomes ashift=12 or ashift=13 currently). You can find discussion on the ZFS subreddit about this pretty commonly, and also on the PostGIS and OpenStreetMap user groups and github issue forums since those people tend to be on the bleeding edge of the disk performance market.