RAID level 5 is the best cost-effective implementation of RAID as it meets all the requirements of a reliable data storage, i.e. performance, fault-tolerance, and storage capacity. It strips data and parity information across three or more drives. It doesn’t employ a dedicated parity drive, instead uses a distributed parity algorithm to strip the parity information. You can easily have your system up and running again after a single drive failure. This can be done by replacing the failed drive with a new one and rebuilding data using the parity information. If more than one drive fails, you cannot reconstruct the RAID array.
More often than not, failures will occur in RAID, as the mechanical drives are doomed to fail after a certain period of use. Further, logical corruption may cause your RAID hard drive to become inaccessible. RAID 5 allows one of the drives in the array to fail to be able to function. However, your system would work in a degraded state following the failure. This means it may stop writing the parity information along with your data. It is more important to back up your data first and then perform the rebuild. If you are unsure that your other volumes are functioning properly or the hardware is not impending a failure, the rebuild operation will involve some risk.
Sometimes, you may end up accidentally reformatting your drives in the RAID. The type of reformat will decide whether you can still recover your business data. In case you are using Windows, the reformatted data will still remain intact as ‘free or unused’ space. If you use an on-board RAID controller utility to do a low-level format, the data on the drive will be completely overwritten. This process might take considerable amount of time to wipe your data.
In the event that two or more drives fail or get severely damaged in your RAID array, you are at the risk of total data loss. In these situations, it is worthwhile to hand over the damaged RAID hard drives to a professional RAID data recovery service provider. These companies possess RAID recovery capabilities to help you get back all the business-critical information from your troubled RAID array. The recovery process involves cloning all the accessible hard drives to prevent further data loss. Next, the failed hard drives are opened in a CLASS 100 Clean Room lab to find out the underlying problem and perform diagnosis. CLASS 100 Clean Room provides a controlled environment that is highly anti-static and dust-free. Once the impacted drives are analyzed, they are made readable for preparing clones. Finally, data recovery is performed from the created drive clones.