I wanted to put some information out there to people if they happen to be using FlexGroups and the powershell toolikt. I was beating my head against a wall for a while trying to get certain options enabled on FlexGroups. From my testing, I found out that some options could not be set until others have been set. It was kind strange. Below is what my end result was that worked. I found I needed to enable volume efficiency first in order to set the fractional reserve or snapshot reserve on the FlexGroup. If I tried to execute the last two lines prior I would get an error saying it could not be done on a mixed volume. Not sure if this is a bug or not, but this was my workaround that worked.
Just a heads up.
New-NcVol -Name $newvol -FlexGroupVolume -AggregateList $aggr1name,$aggr2name -VserverContext $cifsvserver -AggregateMultiplier 2 -JunctionPath $jpath -Size $x.volumeSize -ErrorVariable volError -ErrorAction stop
Get-NcSnapshot $newVol | Remove-NcSnapshot -Confirm:$false -ErrorVariable +nDeployError #cleans up any snapshots
Invoke-NcSSH volume efficiency on -vserver $cifsVserver -volume $newvol
Set-NcVolOption $newVol -VserverContext $vserver fractional_reserve 0 -ErrorVariable +nDeployError #sets volume fractional reserve
Set-NcSnapshotReserve $newvol -VserverContext $vserver 5