Re: [discuss] Illumos future and compatibility with Open-ZFS

[Gea <gea@napp-it.org>]

Thank you for your detailled answer.

I understand the stabilty aspect and value it very high and indeed 
Illumos ZFS has not seen as many problems up to dataloss in 10 years as 
one or the other Linux ZFS distribution in the last year. Unlike Linux 
every Illumos distribution is up to date with a clear and easy way to 
update to newest or downgrade. The OmniOS model of a bloody (current 
Illumos), stable (a freeze every 6 months) and a long term stable, each 
with its own repository undelines this strong focus on stability. This 
is something I don't want to miss so preserve an independent fork. Using 
code from newest Open-ZFS master is surely not a good idea, the question 
is how to take over code from a stable branch ex 2.2.6 or better a 
former with a better stability like 2.2.3 or what TrueNAS is using as 
stable branch.

The real question from a user view is how to preserve compatibility with 
a ZFS pool from a current BSD, Debian, Ubuntu or TrueNAS and when to get 
important Open-ZFS features like ZSTD, Draid, Raid-Z exansion, Fast 
Dedup, direct io or higher limits ex on recsize and much more to come 
while value stability as item2. Stability and compatibility are not 
either or. Find a way to get newer Open-ZFS features including bugfix 
commits with the best achievable stability. Not to have newer ZFS 
features is not an option. Have your cake and eat it.

In a perfect world with endless resources you can check, include and 
maintain every of these features on your own including bugfixes when 
they become known but is this thinkable? I suppose no, so the 
consequence is that you loose compatibility and lack more and more newer 
ZFS features. In the end >95% of all ZFS users are now using Open-ZFS 
and with such many users problem rate is not as bad and bugs are fixed 
in a quite short time.

Maybe a staging model can be one solution like an older more stable 
Open-ZFS branch > Illumos testing > Illumos stable (similar to what 
current Illumos is), just like we see it in Open-ZFS or the OmniOS 
approach or in the Open-ZFS world with Open-ZFS forks on OSX or Windows. 
This would allow newest Open-ZFS features to appear with a delay but to 
appear for sure. Maybe newer long awaited bits like the recent NFS and 
SMB improvements have also a chance to appear in a Illumos testing 
branch for wider testings.

Just one idea but a workable idea how to follow Open-ZFS development is 
critical or user base will lower not from year to year but month to 
month. I can see it in my own user base where most of my former 
Solaris/OI/OmniOS users from some years ago switched to Open-ZFS in the 
meantime, some to Qnap most to Debian/Proxmox/TrueNAS/Ubuntu. This is 
why I also switched my new ZFS client-server cs web-gui to Open-ZFS (any 
OS) without further development in the Solaris/Illumos SE edition beside 
bugfixes.

Gea