Buying all your NAS drives in one batch is a mistake, and I mix brands and dates on purpose

When acquiring new NAS units, I follow a thorough checklist before making the purchase. RAM capacity and type are crucial considerations, particularly if the NAS will run a ZFS-based operating system. However, for the drive selection, I strictly adhere to a policy of mixing and matching hard drives from various manufacturers. This strategy is aimed at preventing simultaneous drive failures, which can cripple a home lab setup.

I also scrutinize the S.M.A.R.T. metrics and perform stress tests on new drives before integrating them into my NAS system. While single manufacturer drives may share firmware or physical issues, purchasing from different vendors decreases the risk of a batch failure. Even though Unraid and some other storage solutions support storage pools built with diverse HDDs, I prefer TrueNAS.

The latter's ZFS file system restricts usable storage capacity to the smallest drive in a vdev, which is why I aim to maintain identical drive specifications across all my storage pools. To further safeguard my data, I use snapshot replication with a spare NAS that receives periodic snapshots from my primary storage server. This setup ensures that even if multiple drives fail, I can restore all the data from my remote server.