An administrator has been instructed to add four additional drives to a server configured with RAID 5. The server is using 146GB drives for the data. Without changing the configuration, how much…

438GB would be the additional space if the four new drives formed a separate RAID 5 array where one of the 146GB-effective drives was dedicated solely to parity for that new sub-array (3 * 146GB). However, when expanding an existing RAID 5, parity is distributed across the entire expanded array.

When drives are added to an existing RAID 5 array that contains smaller drives, the usable capacity of the new, larger drives is limited by the size of the smallest drive already in the array. Thus, each of the four 300GB drives will effectively function as a 146GB drive within the array. For each drive added to an existing RAID 5 array, the additional usable data space increases by the effective size of that drive, so adding four drives yields 4 * 146GB = 584GB additional space.

900GB would be the result if three 300GB drives were used in a new RAID 5, ignoring the constraint of adding them to an existing array of smaller drives.

1200GB would be the raw capacity of four 300GB drives in a RAID 0 configuration, or if the full capacity of 300GB drives were utilized in a RAID 5 without any size limitations from existing drives.