The real reason I wanted to reply to this message is that last line.
wd5 is not being used as a spare. I kind of suspected that might be the case.
(Parts of it might be used for raid0 or raid1, that's a whole different
question and not material here).
Raidframe autoconfigures the in-use components (assuming autoconfig is
enabled for the raid array, which it is for you ...)
| Component label for /dev/wd0f:
| Autoconfig: Yes
(same for the other components.) But spares are not autoconfigured.
If you want a "hot" spare (one that will automatically be used if one
of the other components fails, so you get back the reliability as soon
as possible, in case a second component also fails) rather than a "cold"
spare (one waiting to be used, but which needs human intervention to
actually make it happen - which is what you have now), then you need
to arrange to add the spare after every reboot.
There is no current standard way to make that happen (most of us tend to
be counting pennies, and have no spare drives ready at all - we wait for one
to fail, then go buy its replacement only when required...), so I'd just add
raidctl -a /dev/wd5f raid2