What the fuck is this thing. I keep hearing people talk about it like it's the best filesystem in the universe...

The fact that you've never needed to do this for reasons not associated with Windows suggests you are new.

You'll have better luck waiting for HAMMER2 to be ported to linux, even when its' latest release is still only "experimental".

And things like writing the correct data to the incorrect location. Which is why ZFS always tries to store the checksum away from the data.

FreeBSD doesn't need it because you could put your zpool on GELI devices since day one.

FreeBSD never had serious / working XFS or ext[234]fs support.

Not cross platform though.

Those are absolutely not requirements. You don't need to have an L2ARC or a separate zlog device.

It's recommended to have a 64-bit system because 32 bits of virtual address space isn't quite enough for the way its cache works, but even that's not a hard requirement.

True. If you're constantly moving your disks between machines with different OSes then yeah it's going to be a problem for you.

It can run on 512MB RAM on a 32-bit OS, at least ZoL can. I was an early adopter that found some very strange bugs caused by doing some very odd things.
You might have to flush the caches every few minutes, but it's possible.
A few early ZoL updates destroyed pools.
I remember having panic attacks when shit fucked up during pool updates.

I managed to get it working on a dumpster P3 with 1G RAM and garbage disks.
Would I do it again? Not unless I absolutely have to.

BSDfag here. An appropriately set vfs.zfs.arc_max in /boot/loader.conf and ZFS will be rock solid with whatever amount of RAM you have.