A summary for NVDIMMs would be:
1) Lose power or system crashes - no data loss
2) NVDIMM dies. SLOG no longer used and so system performance drops
3) lose power and NVDIMM dies at the same time (very unlikely) - 5 seconds of data loss
Mirror the NVDIMMs...and then data loss is extremely unlikely except for fire, sprinklers etc.
The TrueNAS M-Series uses mirrored NVDIMMs. The second NVDIMM is on the other controller.
1) Lose power or system crashes - no data loss
2) NVDIMM dies. SLOG no longer used and so system performance drops
3) lose power and NVDIMM dies at the same time (very unlikely) - 5 seconds of data loss
Mirror the NVDIMMs...and then data loss is extremely unlikely except for fire, sprinklers etc.
The TrueNAS M-Series uses mirrored NVDIMMs. The second NVDIMM is on the other controller.