What exactly is RAID?
The acronym stands for “Redundant Array of Inexpensive Disks.” It is a system that allows for a large number of low cost hard drives to be linked together to form a single large capacity storage device.
What then is a RAID 5?
A RAID 5 volume is a combination configured for data to be written across three or more drives. In this configuration, additional data is written to the disk that should allow the volume to be rebuilt in the event that a single drive fails.
But, computer systems do tend to fail at times, and a RAID 5 is no exception.
Understand that there are many reasons for a RAID system to fail (controller failures, software emulator errors, etc.). Therefore, damage to this RAID array, resulting in loss of data, has to be treated as damage on a single disk.
If one of the hard drives in a RAID 5 array becomes corrupted, drops out of a ready state or otherwise fails, the remaining hard drives will continue to operate with no loss of data.
The failed drive can then be replaced in the array with one of equal or larger capacity, and the data it contained will be automatically rebuilt using the parity data contained on the other drives. Result? A RAID 5 recovery.
And if, for example, a file is deleted from a volume residing on a RAID 5 array, file recovery can be attempted using conventional undelete software.
Know as well that data can be recovered from a re-formatted RAID 5 volume depending on how the drives were re-formatted.
Using Windows to re-format a volume, for example, will create what will appear to be a new “clean” volume – but the original data will still be on the disk in the “free and available” space.