All the resources say ZFS doesn't have fsck, or recovery tools, use battery backed SSD for ZIL, etc.
If the plug is suddenly somehow pulled (total power loss despite UPS etc, but assuming no physical damage, no head crashes etc), the SSDs will write cache to nvram and then go quiet….
What chance does ZFS have of being in a consistent state (even if some data was lost) and the pool being usable/readable, when it reboots?
I realise I actually mean to ask something closer to, what events would lead to a situation where ZFS gives up on being able to read the pool, despite the data basically being intact? Its not clear what ZFS can recover from (or can recover given the right hardware) and what it can't (or can't without the right hardware), because it does so much internally to self check and fix things. Clearly insufficient redundancy+ disk failure (or other major hardware issue) is one case, and complete wipe/overwrite due to firmware/software bug is another. But assuming the storage media, hardware and software are still working reliably/properly, what else has to have gone wrong, for the result to be loss of a pool? Where are its limits on pool fixing? Which situations have to arise before it can't, and what has to happen to give rise to them?