Data storage is a rapidly expanding area of consumer electronics because people have growing amounts of data at home along with the fact that they have more than one computer and devices that need to access the same data. Why should consumers have to choose between losing Desperate House Wives or the Final Four games and risk marital stability?Unfortunately, there is a new trend to dumb-down storage for the consumer electronics market by shunning formal RAID technology which I feel is to the detriment of consumers. Consumers often get intimidated by technical terms like RAID storage so I'm going to give the simplified explanation of RAID and explain why it's the perfect technology for consumers.
Some companies have recently begun capitalizing on the fear of RAID complexity that they are advertising the fact that their products don't use RAID. This actually goes against traditional marketing which tends to advertise the fact that a certain product has advanced features, but this new trend advertises the fact that a certain advanced feature is missing. For example, two major products being launched by Data Robotics and Microsoft in the very near term are boasting the fact that RAID (in the formal sense) isn't being used. But at the same time we have new storage products that do advertise RAID capability and the consumer will become more confused than ever whether they need RAID or not.
Data Robotics does a form of proprietary RAID in their Drobo product which seamlessly transitions from data mirroring to data striping with parity and even back to mirroring mode if the device is mostly empty. Mirroring mode is used when there are two hard drives in the device and both hard drives are being used to store the same data twice. That effectively cuts your usable drive capacity in half. When you start adding additional hard drives beyond two, the Drobo device switches to a striping with parity mode though it's not one of the formal RAID Levels. Striping with parity means that the storage device can tolerate a failure in any of the hard drives and still be able to recover the data and repair itself when the bad hard drive is replaced. While the ability to seamlessly flip from data mirroring mode to striping with parity is new and a welcome feature, what's not clear is whether this feature is always useful and it's not clear how well the RAID mechanism performs. The claims of Drobo being able to mix and match drive sizes is also dubious since any difference in capacity between the hard drives in the array is usually unused and left idle. Later on today I'm scheduled to go to Data Robotics' office and check out the device first hand so I'll be updating my review of their product.
Microsoft's new Windows Home Server will use a new feature called "Drive Extender" that seamlessly merges multiple hard drives by doing file-level data striping with the user-configurable option for data mirroring. Even though Windows Home Server has the ability to support software-level RAID from the Windows Server OS and there's no reason it can't support hardware- or firmware-level RAID, those features are hidden to the user and depreciated in favor of Drive Extender technology because Microsoft is afraid that RAID will scare off consumer electronics buyers. Drive Extender has the ability to virtually merge multiple independent hard drives and add internal or external hard drives on the fly so this is definitely a welcome feature for ease of manageability. The problem is that it doesn't use formal RAID technology so it lacks performance and scalability of capacity.
A Windows Home Server user is expected to designate the folders they wish to be fault tolerant and only those folders are mirrored across two hard drives and everything else is only stored once with no fault tolerance. If a user chooses to make all of their folders redundant, then that effectively chops the capacity of the Windows Home Server in half which is not desirable at all and I doubt that any consumer will be happy when they buy two 500 GB hard drives and find out they only have 500 GBs of storage. Microsoft argues that some files aren't important to users and they don't need to be redundant, but why should consumers have to choose between losing Desperate House Wives or the Final Four games and risk marital stability?
The good news about Windows Home Server (or any other custom server running Linux or FreeBSD) is that nothing prevents an appliance maker from using hardware- or software-based RAID Level 5. Nothing prevents them from hiding RAID complexity by implementing seamless RAID expansion with simple wizards that ask the user if they wish to expand their fault tolerant RAID volume whenever a new internal drive is added. When RAID Level 6 technology gets cheaper and more commoditized in the near future, that will provide the ultimate form of fault tolerance because it can tolerate a failure in any two hard drives in the array. RAID Level 5 is the most economic form of redundant fault tolerant storage because you only lose one drive in capacity. If you had 4 hard drives in a RAID Level 5 configuration, your effective capacity is the total capacity of 3 hard drives. If you had 6 hard drives in RAID Level 5 configuration, your effective capacity is equal to the total capacity of 5 hard drives. If one hard drive dies, you can just replace that one hard drive and all of your files are safe. Even though this results in a loss of one hard drive in capacity, it's a small insurance to pay to insure the integrity of all the hard drives in the array. If we were using Drive Extender technology configured to have everything redundant instead of RAID Level 5, we would lose half of the hard drives to redundancy which is a huge waste of storage capacity.
Slower external USB 2.0 devices could be added to the pool of storage using something like Drive Extender and not the RAID volume since it would degrade the performance of an internal RAID, but Windows Home Server would need to be able to distinguish between redundant RAID volumes and non-redundant external drives. The redundant volumes should be used for unique data and the external non-redundant Drive Extender volumes should be used for dumping backup sets from client PCs or used for non-critical data. At this point in time I do not believe Windows Home Server is configured this way but I believe they should consider it. I will check with Microsoft and update this section with Microsoft's response.
Ultimately, most consumers won't understand all these nuances in storage technology and they'll just eat up the marketing and whatever it says on the retail box. I'm going to do my best to educate the public on these things and hopefully influence other technology reviewers to take product vendors to task. Consumers deserve a good experience with technology especially when they're being asked to spend so much of their hard earned money and companies have a responsibility to produce good products.