But how about not using ECC RAM? (Which my box doesn't support)
The most prominent writeup for this topic is a TrueNAS forums post called "ECC vs non-ECC RAM and ZFS" [1]. The author claims that bad non-ECC RAM will cause an explosion of corrupted files in ZFS systems, much much worse than what could happen on non-ZFS ones.
The post is 8 years old, but the problem still seems relevant today, as just 20 days ago I saw an HN user commenting about how they suffered a similar issue [2].
On the other hand, I've seen comments pointing out that ZFS without ECC RAM is not as bad as it has been implied [3]. Some commenter links to a couple places in HN ([4], [5]) where they debunk the logic behind the corruption scenario given in [1].
I guess a fair question would be: What do you want from your NAS?. What I want is to have a relatively unnattended NAS that I can use for weeks or months as my computer's backup, without it silently corrupting my backup files. If a bad non-ECC RAM stick can cause whole file system corruption during a ZSF scrub, I might prefer running Ext4 with something like hashdeep [6], so I can detect the issue, change the bad RAM, and upload fresh backups to the box.
Comments and anecdotes are appreciated!
[1]: https://www.truenas.com/community/threads/ecc-vs-non-ecc-ram-and-zfs.15449/ (Under What happens when non-ECC RAM goes bad in a ZFS system?)
[2]: https://news.ycombinator.com/item?id=29492980
[3]: https://news.ycombinator.com/item?id=27553356
[4]: https://news.ycombinator.com/item?id=8293025
[5]: https://news.ycombinator.com/item?id=14207520
[6]: http://md5deep.sourceforge.net/
[1]: https://www.truenas.com/community/threads/ecc-vs-non-ecc-ram... (Under "What happens when non-ECC RAM goes bad in a ZFS system?")
[2]: https://news.ycombinator.com/item?id=29492980
[3]: https://news.ycombinator.com/item?id=27553356
[4]: https://news.ycombinator.com/item?id=8293025