HOW IS RAID RECOVERY PERFORMED?

RAID recovery can be a very complex process.  It is performed by data recovery technicians in a sterile environment using
special recovery equipment and tools.  The first step is to create a copy of each of the drives in the array.  This allows the recovery technician to work off the copies and should be done in order to preserve the state of the original drives. The next
step the technician will follow is to try to determine the order of the drives.  In many cases, the user already has the proper drive order.  Knowing the order of the drives can save a lot of time and cost in the recovery process.  If the order is unknown, the recovery technician must perform much trial and error in an effort to determine the correct order.  This could sometimes
add days to the recovery time. 

The next step is to determine if the array is a hardware RAID or software RAID.  A hardware RAID is an array that is created using external equipment, typically referred to as a RAID box.  The number of drives varies and is dependent on the array level that exists.  The array is seen as a single volume by the operating system. A software RAID is an array that is created within the operating system and is capable of being accessed by that operating system.

For a hardware RAID, the data recovery technician must first determine if RAID failure is caused by problems with the RAID box itself or if the problem is caused by one or more of the hard drives in the array.  For example, a hardware error residing in the RAID box could cause it to be displaying messages such as RAID configuration error, RAID offline error, or undefined error.  If the problem resides in one or more of the drives in the array, the technician must repair those drives in order for the array to function properly.  For a software RAID, the technician must access the array within the software to make modifications to the array as necessary to recover data.