CompTIA Certification
59 practice questions with correct answers and detailed explanations. Use this guide to review concepts before taking the practice exam.
The CompTIA Server+ (SK0-005) certification validates professional expertise in CompTIA technologies. This study guide covers all 59 practice questions from our SK0-005 practice test, complete with correct answers and explanations to help you understand each concept thoroughly.
Review each question and explanation below, then test yourself with the full interactive practice exam to measure your readiness.
Which of the following BEST describes the purpose of a UPS (Uninterruptible Power Supply) in a server environment?
A UPS provides battery backup power to keep systems running during outages, allowing time for graceful shutdown or failover to backup systems. While voltage regulation is a feature, the primary purpose is temporary power continuity.
What is the primary advantage of implementing RAID 6 over RAID 5 in a production server environment?
RAID 6 uses dual parity and can survive the failure of any two drives simultaneously, whereas RAID 5 with single parity can only tolerate one drive failure. This is critical for large capacity drives with longer rebuild times.
A server administrator notices that CPU usage is consistently at 95% during business hours. Which of the following is the MOST appropriate first troubleshooting step?
Before making hardware changes, the administrator must identify which processes are causing high CPU usage to determine if the problem is application-related, workload-related, or truly hardware-constrained.
Which type of network switch port configuration allows multiple VLANs to transmit traffic over a single physical link?
A trunk port carries traffic from multiple VLANs using tagging (802.1Q or ISL), allowing multiple VLANs to traverse a single physical link. Access ports only handle a single VLAN.
A server experiences intermittent network connectivity issues. Network logs show that the server is losing its ARP cache entries unexpectedly. Which of the following is the MOST likely cause?
ARP cache entries expire based on timeout values; if these are configured too aggressively, entries will be purged prematurely, causing the connectivity issues described. This can be adjusted in OS network settings.
When performing a server backup, which backup method would restore data the FASTEST in the event of total system failure?
A full backup contains all data and requires only a single restore operation, making it the fastest recovery method for total system failure. Other methods require multiple backup sets to be restored sequentially.
A server administrator needs to ensure that a mission-critical database server maintains service availability during hardware maintenance. Which of the following solutions would be MOST appropriate?
Database replication with automatic failover provides true high availability, allowing the service to continue on another server during maintenance without interruption. Other options provide redundancy but not automatic failover.
Which of the following best describes the relationship between thermal design power (TDP) and server cooling requirements?
TDP (measured in watts) indicates the amount of heat a processor generates under maximum load, which directly determines the cooling capacity needed. It is NOT a temperature measurement but a power measurement.
A server's event log shows repeated disk I/O timeout errors on a RAID array. Which troubleshooting action should the administrator perform FIRST?
SMART data and drive diagnostics will identify which specific drive is failing or degrading, allowing targeted replacement rather than unnecessary replacement of healthy drives.
Which of the following scenarios would BEST justify implementing a SAN (Storage Area Network) instead of direct-attached storage?
A SAN is designed for scenarios where multiple servers need shared access to storage, high availability, and centralized management. Single-server scenarios typically don't justify the complexity and cost of SAN infrastructure.
A server administrator is configuring a new physical server and needs to optimize network performance for a high-throughput database application. Which of the following NIC configurations would provide the BEST performance improvement?
RSS distributes incoming traffic across multiple CPU cores/queues, improving throughput and reducing latency for high-performance applications. This is a standard best practice for database servers.
When a server requires security patches, what is the BEST practice for applying them to minimize downtime in a clustered environment?
In a clustered environment, applying patches to one server at a time with failover allows the cluster to maintain availability throughout the patching process. This is called a rolling update.
A server is experiencing memory pressure, with the page file usage increasing significantly. Which of the following is the MOST likely explanation?
When RAM is insufficient, the operating system pages memory to disk (page file/swap space), which is much slower than physical RAM. High page file usage indicates memory pressure and a need for additional RAM.
Which of the following represents the PRIMARY security benefit of implementing firmware updates on server hardware components?
Firmware updates address security vulnerabilities at the hardware and BIOS level, protecting against attacks like Spectre, Meltdown, and other low-level exploits that bypass OS protections.
A server administrator discovers that a physical server's motherboard is failing. Before replacing it, what is the FIRST critical step to ensure data preservation?
Backing up data and configuration is critical before hardware replacement to prevent data loss. While powering off is important to prevent damage, data preservation takes priority.
Which of the following is the BEST description of how processor affinity (CPU affinity) can improve server performance?
CPU affinity pins specific threads to specific cores, which improves cache locality and reduces expensive context switching operations. This is particularly beneficial for latency-sensitive applications.
A server's power supply fails unexpectedly. Which of the following is a sign that the power supply was likely the failing component?
A failing power supply typically causes random reboots under load when it cannot supply sufficient power, especially during thermal stress. This is a classic symptom of PSU failure.
When configuring a server's IPMI (Intelligent Platform Management Interface), which of the following security measures is MOST critical?
IPMI provides out-of-band management access with powerful capabilities; isolating it on a dedicated management network significantly reduces the attack surface and security risks.
A server administrator needs to measure actual disk I/O performance for a production server. Which metric would provide the MOST meaningful representation of overall storage subsystem performance?
Disk queue length and response time under actual workload conditions provide real performance data, whereas theoretical throughput and spindle count do not account for actual usage patterns and overhead.
Which of the following best describes why proper cable management is important in server infrastructure?
Proper cable management improves cooling efficiency by not blocking airflow, reduces the risk of cables being accidentally disconnected, and facilitates maintenance. Poor cable management directly impacts thermal performance.
A server administrator is troubleshooting slow performance on a database server with redundant network interfaces configured. Diagnostics show the secondary NIC is not receiving traffic. What is the MOST likely configuration issue?
If the secondary NIC is not receiving traffic despite being installed, the most common cause is a network layer issue such as the switch port not being enabled or configured for the correct VLAN.
Which of the following scenarios would require the use of a hardware RAID controller rather than software RAID?
Hardware RAID controllers offload RAID processing from the CPU, providing better performance and reliability for mission-critical systems. Software RAID is appropriate for non-critical systems where CPU availability is not a concern.
A server's CPU temperature is reported as 85°C while the motherboard temperature is normal. What should the administrator do FIRST?
A localized high CPU temperature with normal motherboard temperature typically indicates a CPU cooling issue such as improper heatsink mounting or degraded thermal paste. Checking the cooler installation is the logical first step.
When implementing server virtualization, which of the following is a critical consideration for the hypervisor host platform?
Virtualization requires CPU support for hardware extensions and proper resource allocation to the hypervisor for stability. The hypervisor OS is typically specialized and separate from guest OSes.
A server experiencing network latency shows high CPU utilization on a single core while other cores remain idle. Which of the following is the MOST likely cause?
Without RSS or multiqueue support, all network interrupts are processed by a single CPU core, creating a bottleneck and high latency. Enabling RSS or multiqueue distributes interrupts across cores for better performance.
What is the primary purpose of implementing a hot spare in a RAID 5 configuration?
A hot spare is an extra drive that automatically takes over when a drive fails, minimizing downtime. It does not increase capacity or primarily improve performance.
Which of the following best describes the function of a memory parity bit?
A parity bit is used for error detection by checking if data has been corrupted. Single-bit parity can detect but not correct errors.
In a server environment, what is the advantage of using ECC memory over non-ECC memory?
ECC (Error-Correcting Code) memory can both detect and correct single-bit errors, which is critical for server reliability. Non-ECC memory only detects errors without correction.
Which metric is most important when evaluating thermal management in a server?
Junction temperature indicates how close components are to thermal failure. This is more critical than fan count or room temperature because it reflects actual component stress.
What does IPMI primarily enable administrators to do?
IPMI (Intelligent Platform Management Interface) provides out-of-band management access to hardware sensors, logs, and controls independent of the operating system.
In the context of server power supplies, what does PFC stand for and why is it important?
PFC improves power factor efficiency, reducing wasted energy and lowering electricity bills. It also helps comply with power quality standards.
Which of the following would be the best approach to minimize latency in a high-performance server application?
Latency is minimized through fast storage (SSDs), reduced queue depth, and optimized memory access patterns. Adding RAM or cores without optimization won't reduce latency.
What is the primary function of a TPM (Trusted Platform Module) in a server?
TPM is a security device that stores cryptographic keys and performs secure operations like attestation and encryption, protecting sensitive data.
In RAID 6, what is the minimum number of drives required and what is its primary advantage over RAID 5?
RAID 6 requires at least 4 drives and uses dual parity to survive two simultaneous drive failures, which is crucial for large capacity drives with long rebuild times.
What does a POST (Power-On Self-Test) typically check during server startup?
POST is a firmware-level diagnostic that verifies essential hardware components are functional before the OS loads. It does not check OS or application integrity.
Which interface standard would provide the fastest sequential data transfer for server storage in a modern data center?
NVMe PCIe 4.0 provides the highest transfer rates among current standards, with a 16-lane connection supporting up to 64 Gbps, far exceeding SATA and traditional SAS speeds.
What is the primary benefit of implementing redundant network interface cards (NIC teaming) in a server?
NIC teaming provides redundancy so if one NIC fails the other continues operating, and it can aggregate bandwidth across multiple NICs for increased throughput.
In a virtualized server environment, what does CPU oversubscription refer to?
CPU oversubscription means allocating more virtual CPU resources than available physical cores. While this can improve utilization, it may reduce performance if too many VMs are active simultaneously.
What is the primary purpose of implementing a UPS (Uninterruptible Power Supply) in a server infrastructure?
A UPS bridges the gap during power loss, providing time for graceful shutdown or failover to generators. It protects against data loss and hardware damage.
Which of the following is the most critical factor when selecting a processor for a server that will run multi-threaded database workloads?
Multi-threaded database workloads benefit most from multiple cores and threads as they allow parallel query processing. Clock speed is secondary to the ability to execute concurrent operations.
In server storage, what does IOPS stand for and why is it significant?
IOPS (Input/Output Operations Per Second) is critical for random access workloads like databases and transaction processing, not sequential throughput.
What is the purpose of implementing memory mirroring in a server architecture?
Memory mirroring duplicates data across memory channels so if one channel fails, the other maintains system operation. This is critical for high-availability systems.
Which RAID level provides the best balance between performance, storage efficiency, and fault tolerance for most enterprise servers?
RAID 5 offers a good compromise with single drive fault tolerance, efficient storage usage (one drive for parity), and acceptable performance for most enterprise workloads.
What does the term 'headroom' refer to in server capacity planning?
Headroom is the buffer of unused resources (CPU, memory, storage) intentionally kept available to handle peak demand without service degradation.
In the context of server redundancy, what is the key difference between active-active and active-passive configurations?
Active-active distributes the load across both systems for better utilization, while active-passive keeps one system standing by, activating only when needed.
What is the primary advantage of using a SAN (Storage Area Network) rather than direct-attached storage in a server infrastructure?
SAN provides centralized storage that multiple servers can access, enabling better resource utilization, easier expansion, and simplified management compared to isolated direct-attached storage.
Which of the following represents a critical consideration when implementing server firmware updates?
Firmware updates typically require server restarts and should be carefully scheduled during maintenance windows to avoid service interruption and production impact.
What does the term 'Write Hole' refer to in RAID arrays, and why is it a concern?
The write hole occurs when a power failure happens after data is written but before parity is updated, potentially leaving the array in an inconsistent state. Battery-backed cache or journaling mitigates this.
In the context of server networking, what does QoS (Quality of Service) primarily accomplish?
QoS allows administrators to prioritize traffic based on application requirements, ensuring critical services like voice or real-time data get the resources they need even during congestion.
A server administrator needs to configure a RAID 6 array with six 2TB drives. What is the minimum usable capacity of this RAID array?
RAID 6 requires two drives' worth of capacity for parity protection, so with six 2TB drives, usable capacity is (6-2) × 2TB = 8TB.
When should a system administrator implement hot spare drives in a RAID configuration?
Hot spares are beneficial in fault-tolerant RAID levels to automatically replace failed drives and prevent data loss, improving system resilience.
A server is experiencing memory errors detected by ECC. What is the primary purpose of ECC memory in a server environment?
ECC (Error-Correcting Code) memory automatically detects and corrects single-bit errors, which is critical for server reliability and data integrity in 24/7 environments.
Which of the following best describes the purpose of a Trusted Platform Module (TPM) in a server?
TPM is a security component that securely stores encryption keys, enables secure boot, and provides attestation to verify server integrity and prevent unauthorized firmware modifications.
A data center has experienced a power failure affecting multiple servers. After power restoration, several servers fail to boot. Which power-related feature should have been configured to prevent this issue?
Automatic Power On settings prevent boot failures by automatically restoring servers to their previous power state after power restoration, ensuring consistent recovery without manual intervention.
When monitoring server performance, a system administrator observes that CPU utilization frequently exceeds 85% during business hours while memory utilization remains at 40%. What is the most appropriate immediate action?
When CPU is the bottleneck (consistently high utilization) while memory is underutilized, adding CPU capacity or load balancing across multiple servers will provide better performance improvement than adding memory.
A server administrator is implementing a backup strategy and must choose between incremental and differential backups. What is a key difference between these two approaches?
Incremental backups store only changes since any prior backup (requiring less storage but more restore complexity), while differential backups store all changes since the last full backup (requiring more storage but faster restore times).
A virtualized server environment requires the hypervisor to allocate physical resources to multiple virtual machines. Which resource allocation method allows VMs to dynamically use available CPU or memory when not needed by other VMs?
Dynamic resource allocation techniques like memory ballooning and CPU scheduling allow hypervisors to efficiently distribute resources based on actual usage, maximizing overall system utilization.
During a firmware update on a server, the process is interrupted due to a power loss. Which of the following is the most likely result?
Interrupted firmware updates can corrupt the firmware image, potentially rendering the server unbootable and requiring recovery through manual BIOS flashing or hardware replacement.
A server requires the ability to recover from hardware failures without manual intervention. Which clustering technology best provides automatic failover of services to a healthy node?
Active-passive clustering with heartbeat mechanisms detects node failures and automatically transfers services to standby nodes, providing transparent failover and high availability without manual intervention.
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