RAID (Redundant Array of Independent Disks) is an acronym first conceived and implemented in 1988. RAID configurations enable access to multiple individual hard disks presenting them as one larger disk. RAID spreads data storage and access across the multiple disks used in the system, which reduces the risk of losing data if one drive fails. This process is efficient and improves disk access with the added benefit of fault tolerance.
Most IT professionals may dream about large volumes, but big volumes bring bigger problems, so its more critical to understand what type of system should be implemented. Through the years we have seen many combinations of RAID systems, some better than others, but the majority always suffer the same problem, failing hard disks.
RAID 5
RAID Level 5 is commonly referred to as striping with distributed or rotating parity. This type of raid distributes parity among the drives, so no single disk is devoted to parity. This is one the favourite choices in multiprocessing systems. If only one drive fails the raid array can still operate in degraded form. Our data recovery services from this type of raid, are the most common, but this is due to the popularity of Raid 5.
RAID 3
RAID Level 3 is commonly referred to as striping with dedicated parity. This type of raid uses one disk in the system for parity data. The performance in this type of array is also good with simultaneous access to each drive in the array, with the added protection of parity. If one disk fails the data, can be rebuilt from the parity drive. Good data recovery success rates can be achieved from this type of raid array, providing the parity drive survives.
RAID 1
RAID Level 1 is commonly referred to as mirroring across two hard drives. It provides redundancy by duplicating all data from one drive, to another drive. The performance of this type of array is slightly better than a single drive, and if either drive fails, no data is lost unless both drives, the source and mirrored are affected. Data recovery from this type of raid is often software related, but as with all our data recovery techniques, if there is any data on the storage media, then data recovery has almost always been successful.
RAID 0
RAID Level 0, commonly referred to as striping. Data is striped across the drives, resulting in higher data throughput. Since no redundant information is stored, performance is greatly improved, but the failure of any single disk in the array, results in the loss of data affecting any data larger than the stripe length. Data recovery from this type of raid is often limited, but with our knowledge of data recovery techniques and hard disk technology our success rate is amongst the highest in the data recovery industry.
