I am running a TrueNAS (formerly FreeNAS) based server for about six years now. It is currently running TrueNAS 13.0-U6.1. There is a "boot pool" and a "data pool", both installed with the NAS in 2017 and "upgraded" with it from then on.
Recently I noticed that zpool status claims that "some requested features" are not enabled for both pools. Here is the relevant excerpt from the command's output:
pool: data-pool state: ONLINEstatus: Some supported and requested features are not enabled on the pool. The pool can still be used, but some features are unavailable.action: Enable all features using 'zpool upgrade'. Once this is done, the pool may no longer be accessible by software that does not support the features. See zpool-features(7) for details.I do (more or less) understand the "some supported features are not enabled" part, but what are requested features? My guess is that requested features are features that are (were) enabled on the pool once but are not any longer. Only, that seems somewhat unlikely, because the pool was always running on the same machine; I do not recall to ever have enabled and then disabled features again...
My main question now is: (how) can I list requested (and if possible "but not enabled") features? Is there a command for this? I think I would likely enable the "requested but not enabled" features, if I knew which ones these are...
There seems to be terribly little information about requested features in the documentation and the Internet in general.
The secondary question being what requested features are, if someone happens to know?
Any hint would be greatly appreciated.