I imagine the wait was mostly that it wasn't deemed necessary to have ZFS on Ubuntu until now.
Containerisation has drastically increased interest in CoW filesystems. Traditionally their only use-case has been for implementing livecds and similar ro + rw layer environments.
For this AUFS has been the gold standard since basically forever. However AUFS has some flaws and lack of features that make it undesirable to use in production container workloads, hence looking to ZFS to fill this gap.
Note that AUFS has been succeeded by overlayfs which, unlike the various earlier union fs attempts, has actually been merged into the kernel. I'm not sure where it stands with regard to flaws
It's pretty flawed - for example, if you open a file read-only, open it again read-write and the write to it, any read from the first file descriptor won't show the writes. The corner cases don't bite people under most circumstances, but when they do they're awful.
That sounds like a fairly normal structured file/multiprocess workload, not much of a corner case there :(
its still pretty raw. check out cve-2015-8660, which basically let unprivileged users bypass normal file permissions without even trying. it's fixed in mainline now, but still hasn't hit a lot of distros.
Re:ZFS Licensing and Linux
by __michaelg on Friday February 19, 2016 @11:09AM
(#11134320)
Yes. As one of my professors used to say: Using "quite obviously" in non-fiction is quite obviously wrong in most cases.
It is always good to double check things on the off chance that you are wrong. Many of the critics of Canonical's decision cannot claim to have done that.
Perhaps they're exercising due diligence by consulting their lawyers.
What seems obvious to the legal layperson is not always a cut-and-dry issue for the law.
Re:ZFS Licensing and Linux
by lallysingh on Friday February 19, 2016 @11:03AM
(#11134269)
.. because he makes more than 2 conclusions, and the rest aren't "quite obviously" true?
Re:ZFS Licensing and Linux
by ElijahLynn on Friday February 19, 2016 @12:49PM
(#11135077)
Obviously the word obvious is used incorrectly most of the time.
I'm also curious as to why they'd have waited so long to include it if the legal questions were so trivial.