the omnios gcc packages seem to ship .../include-fixed/ which we'd usually rather they didn't.

on the basis we should fix our own headers, and not have surprise copies of our own headers actually get used.

was there a reason for that? did something break?

I'm looking for ZFS opinions. I have 5 20TB drives I'd like to put into a single pool. Which would be more reliable - two sets of mirrors striped or a raidz3?

By "two sets of mirrors" you mean: mirror disk1 disk2 mirror disk3 disk4 disk5 ?

(i.e. mirror(2) + mirror(3) ?)

in the dual mirror the 5th drive would be hot spare

Ahh.

reliability in the sense of how many disks you may lose at the same time?

strip across mirrors has the downside that if you lose both of a pair, you're screwed

I know that was popular for a while (misnomered as RAID10) but wasn't sure if it had gone as out of favor as I thought it had.

The only thing I could think might make a difference with z3 is that all drives are always active, which would not happen to the hot spare in the other configuration

but I don't think that's going to make any real difference.

has the project to add a drive to an existing VDEV ever actually happened?