I'm curious. Could you explain your reasoning with regard to parity RAID? It seems like a good idea on the surface.
Hmm... I could swear we discussed this at some point, but perhaps it was with someone else...
If you wisely subscribe to the tenet that you should have a backup regardless of your primary storage configuration then RAID is unnecessary. And while it may sound convenient to have redundancy, it can be anything but convenient. Parity RAID was designed for business continuity and only makes sense for servers and other mission critical storage where downtime costs money. So unless business continuity is a key requirement, parity RAID makes little sense (at least to me), and in fact, introduces more complications, cost, and potential reliability issues than JBOD (which is why I would never recommend it)...
- Parity RAID is more costly because it requires additional hardware for the parity calculations in order to not impact performance. Plus some of your storage is tied up in unnecessary redundancy (since you maintain a backup anyway).
- Parity RAID adds additional complications in that your storage is not portable so moving or expanding your storage is a tedious task that comes with added risk
- Parity RAID actually introduces added reliability issues since your storage solution is now dependent on an added single-point of failure (e.g. the RAID controller and/or enclosure) and there's the fact that rebuilds of large RAID arrays are often prone to failure due to the time it takes to rebuild and the chance of an unrecoverable error in any the remaining drives which may also be near the breaking point if they are of similar lifespan (RAID5 made sense when disks where 30-300GB in size, it was not designed for arrays of 3TB drives).
So, if you're willing to spend more, give up portability, and introduce some added risk, then parity RAID can be helpful to minimize any potential down time. But I would never recommend this outside of mission critical business situations.
RAID60 is probably the only parity RAID that makes sense for mission critical business storage, and its just not practical outside of those kinds of environments.
The only RAID that really makes sense for SOHO users is RAID0 for performance. Even RAID1 is a waste in everything but the most sensitive data situations, since you must also maintain a separate backup anyway, in most cases (where a proper backup is maintained) it is a complete waste of storage space.