How to fill in the fsid for file systems?

[Andriy Gapon]

On 04/11/2018 17:38, Rick Macklem wrote:
> That leaves ZFS, which is what I was asking.
> I don't understand the ZFS code well enough to understand  what
> dmu_objset_fsid_guid() is doing to get the fsid. I also don't know if the value
> changes for snaphots of the same file system?
> - If it does ever change, then that is the usage case for this option.

A good ZFS example is this.
A filesystem is duplicated using zfs send + zfs recv.  The content would be
exactly the same (provided no modification of the source and the target after
the duplication), but GUIDs of the source and target would be different.  The
latter is required because the source and the target could be in the same pool.
But even if they are in different pools (and different machines), the GUIDs
would still be different.

-- 
Andriy Gapon