I'm thinking of making a mini FreeNAS backup server with 4x 8TB drives. I see 4Kn 512Ke drives out there. I've read 512Ke is bad because of the emulation.
This is only a problem with mis-aligned writes, which require the drive to read a 4K sector, put the modified 512 into it, and write it back. You can address this a number of ways during setup (I'm not sure what FreeNAS does specifically - I use raw FreeBSD).
I think 4Kn is OK if I'm reading right for ZFS in general. Anyone try 4Kn drives with FreeNAS specifically?
You need to have a controller that supports 4Kn. Otherwise it will throw an overrun error when the 513th byte comes along. Also, unless you have a fancy RAID controller that does 4Kn on the drive side and 512 on the host side, you need a UEFI BIOS to boot from a 4Kn drive. That doesn't matter if this isn't also your operating system boot drive (lots of folks use a separate drive, USB stick, or SD card as the boot medium).
I'm using 16 * 4Kn drives on my FreeBSD-based RAIDzilla 2.5 systems and they work fine. I just wanted to point out the potential "gotchas".
