CompTIA Server+

The physical connector on a motherboard where a compatible processor is installed.

An individual processing unit inside a CPU that can execute instructions.

A schedulable path of execution; CPUs with multithreading can run more threads than physical cores.

Error-Correcting Code memory that can detect and correct certain memory errors.

RAM with a register between the memory controller and memory modules to improve stability in servers.

A component that can be removed or replaced while the server remains powered on.

A second or additional PSU that allows the server to keep running if one PSU fails.

A device that distributes power to multiple rack-mounted systems.

Provides temporary battery power during an outage and helps protect against power events.

A rack height measurement equal to 1.75 inches.

A rack-mounted server that uses one rack unit of vertical space.

A rack accessory that organizes cables and allows a server to slide out for service.

A cable termination panel used to organize and connect network cabling.

A switch installed in or near a rack to connect servers in that rack.

A data center layout that separates cool intake air from hot exhaust air.

A panel used to cover empty rack spaces and improve airflow.

A sudden flow of electricity that can damage electronic components.

A grounding strap used to reduce electrostatic discharge risk while handling components.

Low-level software embedded in hardware devices such as BIOS, UEFI, drives, and controllers.

Legacy firmware used to initialize hardware and start the boot process.

Modern firmware interface that supports features such as GPT boot disks and Secure Boot.

A UEFI feature that helps prevent unauthorized bootloaders from running.

Trusted Platform Module; hardware used to securely store cryptographic keys and support platform integrity.

A unique label used to identify and track a physical system or component.

A documented known-good configuration used for comparison, auditing, and troubleshooting.

Documentation listing hardware, firmware, OS, network, storage, and configuration details for a server.

Management access independent of the installed operating system, often through a dedicated management controller.

Intelligent Platform Management Interface; a standard for out-of-band server monitoring and management.

Dell remote management technology for out-of-band server access and control.

HPE remote management technology for out-of-band server access and control.

A device that lets one keyboard, video display, and mouse control multiple systems.

A hardware or software component that manages RAID arrays.

Cache protected by battery so unwritten data is not lost during a power failure.

A carrier or tray used to insert a drive into a server bay.

Host Bus Adapter; connects a server to storage networks or storage devices.

Power-On Self-Test; hardware checks performed when a system starts.

Booting a system from the network to install or load an operating system.

Installing an operating system directly onto physical hardware.

Deploying systems from a prepared OS image to standardize installation.

An OS installation that uses an answer file or automation to reduce manual input.

A standardized, approved system image used as a deployment template.

Dynamically assigns IP configuration to clients.

A defined range of IP addresses available for DHCP assignment.

A DHCP-assigned IP address reserved for a specific device, usually by MAC address.

The temporary assignment of an IP address to a client.

Translates hostnames and domain names to IP addresses.

A DNS record that maps a hostname to an IPv4 address.

A DNS record that maps a hostname to an IPv6 address.

A DNS alias that maps one name to another name.

A DNS record that identifies mail servers for a domain.

A DNS record used for reverse lookup from IP address to hostname.

An IP address manually assigned to a device.

The router address used to reach networks outside the local subnet.

Identifies which part of an IP address is the network portion and which part is the host portion.

A compact way to represent network prefix length, such as /24.

A logical network segment used to separate traffic on shared switching infrastructure.

A user account stored and managed on a single system.

A centrally managed account used across systems joined to a domain.

Assigning permissions to groups instead of directly to individual users.

Granting only the access required to perform a task.

An account used by an application, service, or scheduled task rather than a person.

Software or firmware that creates and runs virtual machines.

A bare-metal hypervisor installed directly on server hardware.

A hosted hypervisor that runs on top of an existing operating system.

A software-based computer that runs on a hypervisor.

A software switch used to connect virtual machines to networks.

A point-in-time capture of a virtual machine state; not a replacement for backup.

A reusable virtual machine image used to deploy new VMs consistently.

A Windows tool used to view system, security, application, and service logs.

A Windows command shell and scripting language used for automation and administration.

Displays detailed Windows network configuration.

Queries DNS records and tests name resolution.

Tests basic IP reachability using ICMP echo requests.

Windows command that shows the route packets take to a destination.

Manages systemd services on many Linux systems.

Views logs collected by systemd-journald.

Protecting information from unauthorized access or disclosure.

Protecting information from unauthorized or improper modification.

Ensuring systems and data are accessible when needed.

Verifying identity.

Determining what an authenticated identity is allowed to access.

Tracking user or system actions for auditing and accountability.

Multi-factor authentication; uses two or more different factor types to verify identity.

Role-Based Access Control; permissions are assigned based on job role.

Access Control List; defines permissions for users, groups, or systems.

Privileged Access Management; controls and monitors elevated access.

Rules for password length, complexity, reuse, expiration, and lockout behavior.

Temporarily disables login after too many failed authentication attempts.

Reducing attack surface by securely configuring systems, services, access, and updates.

The set of points where an attacker could try to enter or affect a system.

A hardening step that reduces unnecessary attack surface.

The process of testing, approving, deploying, and documenting software updates.

An assessment that identifies known weaknesses in systems or configurations.

An approved minimum security configuration used to standardize and audit systems.

A firewall running on a server to control inbound and outbound traffic.

Software used to detect, block, or remove malicious software.

Endpoint Detection and Response; monitors endpoints for suspicious activity and supports response actions.

Security Information and Event Management; collects and correlates security logs and alerts.

The required period that logs are stored for operational, security, or compliance needs.

A record of actions that supports accountability and investigation.

A formal process for reviewing, approving, implementing, and documenting changes.

Data stored on disks, databases, backups, or other storage media.

Data moving across a network.

Protects stored data from unauthorized access if storage is lost or compromised.

Protects data as it moves across a network.

A protocol used to encrypt network communications.

Secure Shell; encrypted remote command-line access.

Remote Desktop Protocol; provides remote graphical access to Windows systems.

Virtual Private Network; creates an encrypted tunnel over an untrusted network.

Controls that protect systems and facilities from physical access or damage.

A controlled entry area that allows only one person or group through at a time.

Physical access control using assigned credentials such as cards or badges.

A lock used to restrict physical access to rack-mounted equipment.

A copy of data used for recovery after deletion, corruption, failure, or disaster.

A complete backup of selected data.

Backs up data changed since the last backup of any type.

Backs up data changed since the last full backup.

A point-in-time state capture; useful for rollback but not a full backup replacement.

A backup that cannot be changed or deleted during its retention period.

A backup disconnected from the production environment to reduce compromise risk.

Physical or logical separation that prevents direct network access to backup or recovery assets.

Keep three copies of data, on two different media types, with one copy offsite.

Recovery Time Objective; maximum acceptable time to restore a service.

Recovery Point Objective; maximum acceptable amount of data loss measured in time.

Mean Time To Repair; average time needed to restore a failed system.

Planning to keep critical operations running during disruption.

Restoring systems and data after a major outage or disaster.

A recovery site with systems and data ready for rapid failover.

Identify the problem.

Establish a theory of probable cause.

Test the theory to determine the cause.

Establish a plan of action and identify potential effects.

Implement the solution or escalate as necessary.

Verify full system functionality and implement preventive measures.

Document findings, actions, and outcomes.

A problem that appears inconsistently, often making logs, baselines, and timing important.

The underlying reason a problem occurred.

A verified working configuration used for comparison during troubleshooting.

A plan to return a system to its previous state if a change fails.

A startup hardware failure detected during Power-On Self-Test.

A RAM-related fault that may cause crashes, corruption, or hardware alerts.

Excess temperature that can cause throttling, shutdowns, instability, or hardware damage.

Automatic reduction of performance to lower temperature.

A cooling failure that can lead to elevated temperatures and shutdowns.

A power supply problem that can cause shutdowns, reboots, or loss of redundancy.

A disk that is no longer operating correctly and may degrade or fail a storage array.

A warning that a drive is likely to fail soon, often based on SMART or controller data.

Self-Monitoring, Analysis, and Reporting Technology; reports drive health indicators.

A RAID array has lost redundancy or a member disk but may still be operating.

The process of reconstructing data onto a replacement disk.

Delay in completing storage read or write operations.

A sign that storage requests are waiting and the disk subsystem may be overloaded.

Loss or misconfiguration of one or more storage paths between server and storage.

A storage adapter reset that may indicate path, driver, firmware, or storage fabric issues.

A network interface or cable connection is not active.

A network mismatch that can cause collisions, errors, and poor performance.

A failure to translate a name to an IP address.

A client cannot obtain automatic IP configuration from DHCP.

An automatic 169.254.x.x address used when DHCP fails on IPv4.

Often causes access to local systems to work while remote network access fails.

Traffic is denied by a host or network firewall rule.

Two services attempt to use the same network port on the same address.

A stopped or failed service can cause an application or function to be unavailable.

A system cannot start the operating system due to hardware, bootloader, disk, or configuration problems.

A Linux/Unix critical OS error that stops normal operation.

A Windows stop error caused by severe OS, driver, or hardware problems.

CPU, memory, disk, or network capacity is consumed enough to affect service.

A process gradually consumes memory without releasing it properly.

CPU resources are fully utilized, causing slow response or processing delays.

A lack of free storage that can stop logs, databases, updates, or applications from working.

An access failure caused by insufficient rights or incorrect permissions.

A TLS or identity certificate is no longer valid and may break secure connections.

System clock mismatch that can cause authentication, logging, or certificate problems.

Virtual machines compete for limited CPU, memory, storage, or network resources.

Too many or long-lived VM snapshots consuming space and hurting performance.

Comparing current performance or configuration to a known normal state.

Direct-Attached Storage; storage connected directly to a server.

Network-Attached Storage; file-level storage accessed over a network.

Storage Area Network; block-level storage accessed over a dedicated storage network.

Storage presented as raw blocks, commonly used by SANs and databases.

Storage presented as shared files and folders, commonly used by NAS.

Storage that manages data as objects with metadata, often used for scalable unstructured data.

Logical Unit Number; a logical block storage volume presented to a server.

A protocol that carries SCSI storage commands over IP networks.

A high-speed storage networking technology commonly used for SANs.

Network File System; a file-sharing protocol commonly used by Unix/Linux systems.

Server Message Block; a file-sharing protocol commonly used by Windows systems.

Allocating logical storage capacity that may exceed currently committed physical capacity.

Allocating physical storage capacity upfront.

Eliminating duplicate data blocks to reduce storage usage.

Input/Output Operations Per Second; a measure of storage performance.

Striping only; improves performance but provides no redundancy.

Mirroring; duplicates data across drives for redundancy.

Striping with distributed parity; requires at least three drives and tolerates one drive failure.

Striping with double distributed parity; requires at least four drives and tolerates two drive failures.

Striping plus mirroring; requires at least four drives and provides strong performance and redundancy.

A standby drive that can automatically replace a failed RAID member.

Redundancy information used by some RAID levels to reconstruct lost data.

Allocating storage capacity to servers, applications, or users.

Estimating future storage needs based on growth, usage, and retention requirements.