On Mi, 2021-06-09 at 11:06 +1000, Aleksa Sarai wrote:

On 2021-06-08, Martin Wilck wrote:

...

RENAME_EXCHANGE has been part of the official kernel since 3.15 (2014). Adapting to new Linux VFS features is obviously low on the openZFS developers' priority list. That's their decision. But it means that people should think twice before using this file system, in particular as root FS.

To play devil's advocate, not all in-tree Linux filesystems support RENAME_EXCHANGE either (in fact, most don't[1] -- though the most popular ones obviously do). To be fair, none of those filesystems are supported as a root partition on openSUSE either, but it's a bit unfair to pretend that this is somehow a ZFS-specific thing.

Fair enough. I didn't mean to pretend it was ZFS-specific. I was trying to point out that the choice of the root FS should be made with care, and that the recommendation of the distro one is using should be an important part of the consideration. NFS is interesting, as NFS root used to quite popular some years ago. No idea if folks are still using it though.

But as it happens, I worked on a patch some time ago to add RENAME_EXCHANGE support to OpenZFS[2]

I saw it. Good work. Let's hope it'll get merged. Regards Martin