The most common failure for a RAID array is due to a failure of the hard disk drives, but when the hardware containing these disks failures, your actions can be just as critical for the safety of your data. Although extremely inconvenient, this type of failure will cause the RAID to completely fail, which avoids the possibility of continuing to write data to hard disk drives that are starting to fail.
Many RAID arrays, especially those in the enterprise market will contain redundant power supplies, reducing that a possible failure mechanism for many. The worst type of hardware failure is when the backplane or RAID controller fails, as replacing these can often lead to a loss of the RAID configuration. If this happens, it is essential to call a professional RAID data recovery company, who can assist you in ensuring that the data is recovered without risking any loss.
Lost RAID Configuration
Besides hardware failure the RAID configuration can also be lost due to firmware issues or operator error. Unless you are absolutely one hundred percent certain that you can restore the RAID configuration with damaging the data, there should be no attempt to correct the problem.
Creating or restoring an incorrect configuration will not only cause the data volumes held on the RAID array to be corrupt, but could lead to further damage. More dangerous than the integrity check done by the RAID array, is how the operating system may react to a damage or corrupt data volume. It is essential to call for professional help before a mistake is made, which could have serious ramifications for the integrity of your data.
RAID Volume Corruption
In the event of corruption to, or creating the wrong RAID configuration, it is important to avoid bringing the RAID array back on-line. When an operating system sees a data volume, it will attempt to mount it, which includes checking the integrity of the system data structures. If these are found to be inconsistent, the operating system will attempt to rebuild the system and file metadata. If the operating system is allowed to attempt to fix a file system held on a RAID array with the wrong configuration, severe destruction of data could result.
RAID Data Recovery
The best chance for a successful data recovery is when no attempts have been made to fix the problem which could have caused any corruption. The use of an incorrect RAID configuration, particularly if the data striping or RAID type is incorrect, could cause damage which may be irreparable.
It is of great importance not to panic and make a mistake which could result in a total loss of data. The use of a RAID array usually indicates that important data is being stored, which should never be put at risk.