In reply to your (edited out) comment that "ZFS saw poor adoption":
You might not know it, but out of all the new filesystems designed after 2005 (a few dozens?), ZFS appears to be the one that has seen the fastest adoption/growth [1].
Source: my anecdotal experience in the industry, the experience of many of my colleagues, random consultants reporting "I've seen 1000's of large ZFS deployments" [2], etc.
[1] Outside of ext4 which was introduced in 2006 and was a simple refresh of ext3, not really a "new" filesystem.
Note that ZFS began development in 2001, not 2005, so ZFS itself isn't a new filesystem designed after 2005. The ZFS source code was first released in 2005, but it was announced a year prior. In any case, ZFS is actually somewhat older.
To turn your question around: what new serious [1] filesystems have been designed since 2005 (or 2001) at all, regardless of adoption?
I think that the answer is actually far less than a few dozen. I can think of four: ext4 (as mentioned), F2FS (announced 2012, started ?), btrfs (started 2007), and ZFS (2001).
Maybe there are others, I don't know, but I don't really think there are even that many contenders for adoption. (If there are, I'd be interested to find out).
[1]: By serious I mean in a sense similar to what is outlined here:
in particular "In specific, none of these alternate init systems did the hard work to actually become a replacement init system for anything much", but for filesystems instead of init systems. For example, I would not consider HAMMER to be a 'serious filesystem' for the purposes of this list, whatever its technical merits.
There was a joke when Microsoft was pushing Zune that it has the fastest sales growth "in the brown MP3 players market".
The category you define may be seen as arbitrary, first because existing filesystems have not stopped evolving. HFS, NTFS and so on have been significantly improved over time, including after 2005.
ZFS is a categorically different concept than said examples, in that it's distributed.
But the file system has not been shown to be the best (or let alone only) way to have distributed data, you can easily put that at a higher level, and retain the flexibility of defining your own protocol with the consistency, consensus algorithm and other properties you precisely need.
Why solve this at the file system and lock yourself to a single system-wide way of doing it, versus have the best solution for each part of the system? I feel like it causes more troubles than it solves.
> ZFS is a categorically different concept than said examples, in that it's distributed.
What? No, ZFS is not a distributed filesystem. It never has been, it almost certainly never will be, and it has little in common with distributed filesystems.
What makes ZFS different is that it is a production-grade copy-on-write self-validating merkle tree. Most of its properties fall out from that. There's nothing distributed there.
I'm saying this in the kindest way possible: please don't write about things that you have zero idea about. You cannot possibly be more fundamentally wrong about ZFS, and nothing you wrote makes any sense. :(
You might not know it, but out of all the new filesystems designed after 2005 (a few dozens?), ZFS appears to be the one that has seen the fastest adoption/growth [1].
Source: my anecdotal experience in the industry, the experience of many of my colleagues, random consultants reporting "I've seen 1000's of large ZFS deployments" [2], etc.
[1] Outside of ext4 which was introduced in 2006 and was a simple refresh of ext3, not really a "new" filesystem.
[2] http://nex7.blogspot.com/2013/03/readme1st.html