After expanding an existing disk array on a Linux file server, a systems administrator observes reduced performance during write operations. The original configuration consisted of four disks managed by the server's hardware controller, and a fifth disk was introduced to enhance storage capacity. What is the most probable cause of the observed decrease in write operation speed following the expansion?
The block size of the array is not properly configured for the number of disks, leading to inefficient write operations.
The overhead of parity calculations is higher now with the additional disk, slowing down the overall write performance.
The recent disk added to the server is defective, causing a delay in the array's ability to write data effectively.
Suboptimal cable quality is causing a bottleneck in data transfer between the controller and the disks.