Which RAID Configuration Works Best for Your Business?

One immutable rule of business and data storage states that as a business grows so do its storage needs. Not just in terms of capacity either, performance and reliability must also scale with the business. To meet those expanding needs, SMBs often implement RAID arrays since they can improve data storage performance and reliability. But which RAID configuration offers the most benefits for SMBs? Find out below.

Short for redundant array of inexpensive/independent disks, RAID enables physical storage drives to be consolidated into a single or multiple virtualized drives. You can choose for the virtualized drive to execute read/write operations quicker, have data redundancy, or both. The type of RAID configuration used determines what the performance benefits will be.

Standard RAID Configurations

• RAID 0 (Data Striping) – Data is written across all the drives in the array. Drive 1 gets one bit, drive 2 gets another, and so on. Each drive holds just one portion of a file, as files are segmented—or striped—across drives, hence the term data striping. With RAID 0 read and write performance increases because the drives work simultaneously to access data. So instead of one read operation happening, you have several at the same time.However, RAID 0 lacks data redundancy and if one drive fails, the data on that drive is lost.
• RAID 1 (Data Mirroring) – The configuration synonymous with redundancy, all hard drives in the array store the same data. Data on one drive gets mirrored exactly to another, hence the term data mirroring. So if one drive fails, your files and folders are not lost. In RAID 1, read performance can increase because each drive reads different portions of a file simultaneously. However, write performance does not receive any benefits.
• RAID 5 (Data Striping with Parity) – RAID 5 requires at least three drives. Data is striped across two or more drives like in RAID 0, with one drive being reserved for parity. Without getting overly technical, parity is a value calculated from the combination of two hard drives. When one hard drive fails, the data from that drive can be recovered by working backwards, like an algebraic equation.Written as an equation, it would be: x + y = z
  x = drive 1
  y = drive 2
  z = parityProvided have two variables, you can always calculate for the third. RAID 5 features fairly quick read performance, but suffers slower write performance and rebuilding data because of a failed drive can be a slow process.The slower write performance results from the array having to calculate parity each time it writes data. Because RAID 5 offers some performance benefits and a degree of data redundancy, some network attached storage (NAS) and RAID appliances come from the factory preconfigured for RAID 5. Shawn Chu from QNAP recommends this setting for SMBs because it boosts read/write speeds while still being able to function when one drive fails, “SMB customers prefer using RAID 5 or RAID 6 over RAID10 for NAS RAID configurations.”  In a small- to medium-sized office, an NAS RAID array needs to be fast enough to serve multiple users simultaneously while offering a degree of data protection at the same time.
• RAID 6 (Data Striping with Additional Parity) –. In a RAID 6 array, up to two drives can fail before data becomes unrecoverable. Like RAID 5, write operations and data rebuild times require more time. Compared to RAID, 5 rebuilding data lost in a RAID 6 array can be significantly longer. The main benefit of RAID 6 is that data can be recovered even when two drives fail, while RAID 5 only allows recovery if one drive fails.
• RAID 10 (Data Striping and Mirroring) – RAID 10 is also known as RAID 0 + 1 or “One Big RAID 10” (OBR10). RAID 10 requires a minimum of four drives.
  The drives are grouped into two RAID 1 arrays, which are in turn both striped. RAID 10 offers both performance and data redundancy since data can be recovered from one group of drives if the other group fails. However, a RAID 10 array costs the most to implement and expand. In order to add storage space to your virtualized volume, you need to purchase drives for both mirrored sets. In a basic RAID 10 setup, you’ll need to purchase 4 storage drives in order to expand capacity.

Which RAID Configuration Should a SMB Use?

RAID 0 and 1 offer basic RAID functionality but typically do not meet the data needs of SMBs. RAID 0 does not offer any protection from failure while RAID 1 performs slower than RAID 5, 6, or 10.* Those three offer the most amount of benefits for SMBs as they perform quicker than RAID 1 and also offer protection from data loss unlike RAID 0. As for deciding between RAID 5, 6, and 10, the decision comes down to cost, performance, and protection.

If cost of is a concern, RAID 5 and 6 are ideal. “Businesses with limited budgets can still enjoy increased read performance with RAID 5 or 6 configurations while keeping costs low,” Chu says. As a centralized office storage solution, those configurations perform very well.

For big data operations such as server farms and data centers however, where budgets will be bigger and performance more important, RAID 10 still offers the most benefits. So if you plan to implement storage servers instead of desktop NAS appliances, RAID 10 will likely be the better solution. In addition, the prices of hard drives and solid state drives have dropped significantly in the last few years, so expanding a RAID 10 array can be accomplished at lower cost than ever before.

So how do I set up a SMB RAID Configuration?

Setting up a RAID array can be done one of two ways: hardware or software. You can purchase  storage appliances, RAID expansion cards, and select motherboards specifically designed to support RAID arrays, and those often include additional features and functions that make management easier. The software route requires an operating system that supports RAID setup, such as Windows 7. Many SMBs opt for a hardware RAID solution as they typically have larger feature sets.

For example, the QNAP TS-869L-US desktop NAS, as well as select models from Synology, Netgear, and more, allow for hot swapping of drives in RAID arrays. So when a drive fails, it can be quickly replaced without powering down the devices. From a user standpoint, there will be minimal downtime. In addition, setup and management of RAID configurations are made easier with a hardware solution—especially with desktop appliances and enclosures. Some cloud models feature management portals that can be accessed via IP from within the network or from an online management portal if outside the network.

There you have it, RAID 5/6 for the budget minded and RAID 10 for big data and performance. RAID arrays will benefit any SMB planning to implement a network storage solution. What are your thoughts on SMB RAID configurations though? Let us know what RAID configuration you use for your SMB’s NAS devices.

*Some IT professionals have pointed out that the performance difference between RAID 1 and RAID 5 can vary depending on the capabilities of the hardware controller, write speed especially so.