My NS4700 has 4x 3TB HDDs in a RAID5 setup. One of these drives recently died, and the array went into "degraded" state.
I have replaced the failed drive with an identical one (down to submodel and firmware version), but the drive is in "unconfigured" state, and I do not have the option to start a rebuild (greyed out due to no "spare" or "dead" drive).
I cannot turn off the "auto rebuild" option (to see if that would enable the "rebuild" button), as any time I try and change that setting and apply it, I simply get a spinning wheel for a fraction of a second, and nothing happens - going back to that settings screen shows auto rebuild ticked again.
I cannot change the state or assignment of the drive, and cannot find a way of initiating the rebuild - is there another method to forcibly start an array rebuild?