If you RAID configuration is lost or deleted, it is important not to panic and make an ill-advised attempt at recovering it that could put your data at risk. To determine the configuration of a RAID array usually takes a combination of experience and an in-depth knowledge of the underlying file system, a task which should be left to a data recovery expert.
There are several ways in which the configuration can become lost such a hardware failure, logical corruption of the configuration data or accidental deletion. In all cases you should immediately contact a professional data recovery company, who can guide through sending your hard disk drives so that your files can be recovered.
Some RAID cabinets store the configuration in a chip on the controller board, which is accessed when the system is powered on. The downside of this approach, is that should the controller board or the chip fail, and need to be replaced, the configuration will be lost. Attempting to reconfigure the RAID array would risk damaging the data contained on the drives.
Many dedicated RAID arrays and those created through the operating system, will usually use the logical volume manager (LVM) for storing the information used to determine the configuration at boot time. This approach keeps the configuration closely tied to the RAID, such that the need to replace any hardware should not have any effect on this data. Should the LVM become corrupt due to malicious software or an unreadable bad sector, the operating system will be unable to mount the RAID volume.
Deleted RAID Configuration
Deletion of a RAID configuration can happen as a malicious action, although in most cases it is simply down to user error, often caused by attempting to hurry when reconfiguring systems. The consequences of this are very much the same as those due to a hardware failure or logical corruption, in that the RAID volume will become inaccessible.
Never Reconfigure the Array
Even if you were told at the time the RAID array was installed that it contains a specific configuration, never attempt to reconfigure using that information. We have seen many cases where a customer has been told they are using a particular RAID configuration, but upon inspection it is apparent a totally different one has been used.
Reconfiguring the RAID may have a small chance of success, but should it be incorrect, it may render your data totally inaccessible, or in the best case, data recovery may be possible, but a much more complex process than it should have been.
RAID Data Recovery
As with any hard disk drive which arrives, our data recovery specialists will secure a sector-by-sector image copy of each drive before the full recovery process can be completed. Our RAID data recovery engineers inspect the images to determine the RAID configuration using their in-depth knowledge of file systems. In the case of losing a RAID configuration, our success rates are extremely high.