High Availability
The cornerstone of SmartStyle’s high availability rests in a revolutionary cloud file system. BitSpread technology ensures data is preserved the moment it is written. Disk Spread Policies determine how many hard drives data is written across in a way that X many of those drives can fail before there is data loss. For example, a typical SmartStyle policy is written such that data is written over fifteen hard drives so that seven hard drives can fail before you would lose any data.
By writing data using BitSpread, the probability of loosing data is severely lowered. Data is written using Forward Error Correction (FEC) where each data write includes redundant data, known as Error Correction Code (ECC). The ECC can be used to reconstitute lost data. This helps prevent unnecessarily resending the same data should a transmission fail.
The algorithms behind BitSpread are based on coding theory allowing for error detection and correction. As hard drives in the spread fail the algorithms continue to recreate the lost data. As hard drives are added back into the equation, they are once again incorporated into the BitSpread. Data is regenerated over time.
BitSpread allows for hot adding storage capacity with no recreation required. Rebuilds do not have a performance impact on the virtual machines running. As more nodes are added to a SmartStyle, the capacity and the reliability both increase.
BitSpread resembles the popular puzzle game Sudoku where an entire grid of numbers can be reconstituted from knowing only a few basic rules and a handful of numbers.