Signal blocking is a technique that prevents or reduces the transmission of electromagnetic signals from a building to the outside. Signal blocking can be achieved by using materials that absorb, reflect, or scatter the signals, such as metal, concrete, or mesh. Signal blocking can protect the data center from eavesdropping, interference, or jamming by unauthorized parties1.
Camouflage is a technique that disguises or conceals the appearance of a building to make it less noticeable or identifiable from the outside. Camouflage can be achieved by using colors, patterns, shapes, or vegetation that blend in with the surrounding environment. Camouflage can protect the data center from detection, reconnaissance, or targeting by hostile parties

After removing the virus from the server, the administrator should perform the following actions to mitigate the issue from reoccurring and to maintain high availability:
Run a vulnerability scanner on the server to identify any other potential weaknesses or exposures that could be exploited by attackers.
Patch the vulnerability that allowed the virus to infect the server in the first place, using the latest updates from the database software vendor or a trusted source.
Update the antivirus software on the server to ensure it has the most recent virus definitions and can detect and prevent future infections. The other options are either unnecessary or counterproductive for this scenario. Repartitioning the hard drive, reformatting the OS, removing the database software, or air gapping the server from the network would cause downtime and data loss, while enabling a host firewall would not prevent a virus infection from within the network. References: CompTIA Server+ Certification Exam Objectives, Domain 5.0: Security, Objective 5.2: Given a scenario involving a security threat/vulnerability/risk, implement appropriate mitigation techniques.

The technician should configure RAID 6 for this drive array to meet the server specifications. RAID 6 is a type of RAID level that provides fault tolerance and performance enhancement by using striping and dual parity. Striping means dividing data into blocks and distributing them across multiple disks to increase speed and capacity. Parity means calculating and storing extra information that can be used to reconstruct data in case of disk failure. RAID 6 uses two sets of parity information for each stripe, which are stored on different disks. This way, RAID 6 can handle up to two disk failures without losing any data or functionality. RAID 6 also allows for the least amount of drive space lost to RAID overhead compared to other RAID levels that can handle two disk failures, such as RAID 1+0 or RAID 0+1.
Reference:
https://www.booleanworld.com/raid-levels-explained/