Sakis is also concerned about the availability of data stored on each office's server. He would like to add technology that would enable continued access to files located on the server even if a hard drive in a server fails. What control allows him to add robustness without adding additional servers?

RAID uses additional hard drives to protect the server against the failure of a single drive or two, based on the RAID level selected. Load balancing and server clustering do add robustness but require the addition of a server. Scheduled backups protect against data loss but do not provide immediate access to data in the event of a hard drive failure.