RAID is an acronym for Redundant Array of Independent Disks or Redundant Array of Inexpensive Disks. It improves disk read/write operation/processing and incorporates fault-tolerance features. To some extent, data recovery is built into RAID systems.
A RAID array will have a number of disk drives, all controlled by 1 RAID controller (either physical or logical). The controller manages all the different drives and presents a single logical data view to the system. The drive control function may provide distinct kinds of drive management utilities, such as scanning or formatting a the disk.
Redundancy is built in with the system being able to continue to work even if one of the drives fails. A complex mathematical logic ensures that the system can continue read/write operations even if 1 disk is offline.
The logical array ensures balanced data read and write operations. Instead of overloading just one disk with all the work, the data streams across all the physical drives.
2011 Best of Honolulu Award for Data Recovery
RAID Recovery
RAID recovery procedures require a high level of technical skills and specialized resources. The procedure starts with rebuilding the logical array. The logical array represents the integrated data view. The original configuration of the RAID system is restored through the array rebuild and this ensures that the next step of file system repair is error totally free.
If you attempt file system recovery with out first rebuilding the array, a huge number of errors could result and the file system can get corrupted. The array rebuild must only be attempted by persons with the requisite level of technical know-how. This is something that few data recovery organizations can arrange make positive the one you have found can do this sort of work.
The correct rebuilding of the RAID array ensures quality data recovery and might need the rebuilding of individual drives prior to the rebuild for instance if the server was in a fire or flood. Do not be tempted to just RAID controller. This is a hit or miss and can result in further damage to the array.
RAID data recovery involves additional complexity because there are distinct RAID levels, RAID controllers and RAID architectures. Drives utilized can also be various in kind, make or model. The reasons for data loss can also be varied and can call for distinct kinds of recovery approaches.
With such a range of complexity, RAID data recovery is not something that can be attempted by just any data recovery organization.
RAID Levels
Based on distinct data storage schemes, various RAID levels have been standardized. Starting at RAID 0, there here are diverse schemes which give appropriate solutions for data protection, performance and reliability. Various nested levels are also implemented like RAID +1, RAID 5+, RAID 5+1 and so on.
When 1 or far more RAID drives fail, various RAID data recovery tools are required for various RAID arrays. Such RAID data recovery tools depend upon the nature of failure that is regardless of whether logical or physical drive failure. Here are the most common types of RAID levels:
- RAID 0 - Striping (performance)
- RAID 1 - Mirroring (fault-tolerance)
- RAID 5 - Distributed Parity (higher performance + redundancy)
- RAID 0+1 - Mirroring + Striping (performance + fault-tolerance)
- RAID 0+5 - Distributed Parity + Striping (increased reliability and performance)
Conclusion
RAID data recovery is technically an extremely challenging job. Automated recovery attempts can lead to corrupting the file systems, and making the scenario even worse. The RAID array has to be rebuilt properly, before file system repair is attempted.
RAID systems can be various in their architecture and hardware components, and data loss can happen from varied causes. These factors also make it important that only experienced RAID data recovery specialists should be entrusted with your RAID data recovery job.
