We’ve re-built all RAID configurations on the NAS to use many RAID-Z1 (4-wide) arrays, up from 3-wide.
There is also now a hot-spare amongst the configuration, meaning if a disk fails, the system will swap-out & into service. This retains the 3-way SSD Mirror for small-block (metadata etc) I/O performance improvements. Work continues on final configuration now we’re at a hardware resting state, then integrating with DirectAdmin.