To be clear, it is not ZFS that requires or even mandates ECC. Since ZFS uses data as present in memory and has checks for everything post that, it is prudent to have memory checks at the hardware level.

Thus, if one is using ZFS for data reliability, one ought to use ECC memory as well.

> Actually it seems ECC is important for ZFS filesystems see:

The inflection made by the previous comment tends to lead people to think ECC RAM is needed for ZFS specifically. As the blog post you link to points out it's equally applicable to all filesystems.

It's not required, but it doesn't make sense to use ZFS but not to use ECC memory. That's the point. It's like locking the backdoor but leaving the front door wide open.