AUTOREPLACE=ON not automatically replacing failed drive with hot spare?

pfBasic

If I'm understanding it correctly, adding a spare to your pool and setting autoreplace=on means that if your pool is degraded, ZFS will automatically re-silver your pool using the designated spare.

I tested that in a VM just to see exactly how it would work for an actual drive failure, and it didn't.
It just doesn't do anything.
I tried off-lining a disk then running zpool status, but it just showed degraded, the spare still showed available and no re-silvering was taking place.
I tried running a scrub and it scrubbed successfully but still no re-silvering.
I rebooted and still nothing.

I tried removing a disk from settings while the system was shutdown, then starting up. Same effect, I tried rebooting and still nothing.

running zpool replace successfully resilvered the pool.

So reading up on this I see some documentation from oracle that is confusing to me:
http://docs.oracle.com/cd/E19253-01/819-5461/6n7ht6qvt/index.html

Automatic replacement – When a fault is detected, an FMA agent examines the pool to determine if it has any available hot spares. If so, it replaces the faulted device with an available spare.

Suggests that everything is automatic when a disk fails.
Seems to conflict with:
http://docs.oracle.com/cd/E19253-01/819-5461/gbcet/

Note –
If you had previously set the pool property autoreplace to on, then any new device, found in the same physical location as a device that previously belonged to the pool is automatically formatted and replaced without using the zpool replace command. This feature might not be supported on all hardware.

Sounds like I have to physically place the spare into the slot previously occupied by the failed drive in order for this to work? This seems pretty useless though.

So which is it, does autoreplace=on really automatically replace a failed disk with the designated hot spare, or do I still have to physically move the drive connection?
If it is automatic, is it broken in 2.4.0 BETA, or am I doing it wrong?

doktornotor

You'd need zfsd for this.

https://svnweb.freebsd.org/base?view=revision&revision=300906

pfBasic

OK great thank you!

Are there's any plans to bring this to pfSense as a package for 2.4?

doktornotor

No clue whatsoever.

pfBasic

@pfBasic:

OK great thank you!

Are there's any plans to bring this to pfSense as a package for 2.4?

It's actually already natively part of FreeBSD 11.

zfsd

Starts the daemon.
I couldn't find a man page for it online but there's one on FreeBSD.
I don't know how to make that command run on boot but I'm betting even I can figure it out with a little searching.

EDIT:
Yup, even I figured it out. Install the shellcmd package and add zfsd.

ps -auxww to see if the daemon is running.