RAID 1 A RAID Level 1 also requires a minimum of 2 drives to setup. In some instances, a RAID 1 array can recover from multiple and simultaneous hard drive failures, it also uses the simplest data storage design. For the best performance possible, the RAID controller must be able to perform two separate concurrent reads per mirrored pair, or two duplicate writes per mirrored pair. The overhead for this particular configuration is very high...100%. For this reason, RAID 1 often times is not be ideal for a large server.
