CompTIA A+ Core 1 (220-1201) flashcards

Flat flexible cables connecting internal laptop components like touchpads and keyboards to the motherboard.

• Can loosen or disconnect during disassembly
• Reseating is the first troubleshooting step
• Damage to the cable itself may require replacement

Memory trick: Loose cable, loose function—reseat before you replace.

NVMe (Non-Volatile Memory Express) is a protocol that lets SSDs communicate directly over the PCIe bus, bypassing the slower SATA/AHCI interface.

• Uses M.2 slot with PCIe lanes
• Much higher bandwidth than SATA III (6Gbps)
• AHCI is the older protocol used by SATA SSDs

Memory trick: NVMe skips the SATA traffic jam and drives straight on the PCIe highway

The ST (Straight Tip) connector is a fiber optic connector that uses a bayonet-style twist-and-lock coupling mechanism, similar to a BNC connector.

• Uses bayonet twist-lock coupling
• Older style connector, still used in some legacy installs
• Differs from push-pull LC and SC connectors

Memory trick: 'ST' = 'Spin and Twist' to lock it in place.

The process of transforming a digital video signal (e.g., HDMI, DisplayPort, DVI-D) into an analog video signal (e.g., VGA), which typically requires an active adapter.

• Digital: HDMI, DisplayPort, DVI-D.
• Analog: VGA.
• Active adapter needed for digital to analog conversion.
• Passive adapters often work for analog to analog or digital to digital if compatible.

Memory trick: Digital to Analog, active adapter's the call, or your screen won't show it all.

When a USB device is not recognized despite power and physical connection, the next step is to check Device Manager for driver issues, unknown devices, or device status.

• Verify physical connection and power first
• Rule out faulty cables or ports
• Device Manager shows OS hardware status
• Driver issues are common for new/problematic devices

Memory trick: Device Manager Detects Driver Deficiencies.

Error-Correcting Code (ECC) memory includes additional circuitry to detect and correct common types of internal data corruption, crucial for servers and critical systems.

• Unbuffered ECC (UDIMM ECC) is common in entry-level servers and workstations.
• Registered ECC (RDIMM ECC) uses a register to buffer data, improving stability and scalability for higher capacities.
• Load-Reduced ECC (LRDIMM ECC) uses a memory buffer to reduce electrical load, enabling even higher capacities.
• ECC and non-ECC memory are generally not interchangeable on the same motherboard.

Memory trick: Servers 'R.U.L.E.' with RAM: Registered, Unbuffered, Load-reduced, ECC.

The process of selecting appropriate Wi-Fi channels to minimize interference and maximize network performance in a given environment.

• In 2.4 GHz, channels 1, 6, and 11 are non-overlapping.
• Channel selection is critical in dense environments with multiple access points.
• Proper channel planning reduces co-channel interference and improves throughput.

Memory trick: To avoid a Wi-Fi fight, pick a channel that gives space and light.

File Transfer Protocol uses TCP port 21 for control commands and TCP port 20 for the actual data transfer.

• FTP is unencrypted; FTPS or SFTP should be used for security
• Port 21 handles commands like login and directory listing
• Port 20 handles the actual file data in active mode

Memory trick: Twenty carries data, twenty-one gives commands.

A software-based network switch that operates within a hypervisor to enable communication between virtual machines on the same host and connect them to physical networks.

• Functions like a physical network switch.
• Connects VMs to each other.
• Connects VMs to the external physical network.

Memory trick: The 'V-Switch' connects 'V-Machines' like a real switch.

The principle in virtualization that ensures each virtual machine operates independently of others on the same physical host, preventing interference in terms of security, performance, and resource usage.

• Each VM has its own virtual hardware and OS.
• Prevents security breaches between VMs.
• Ensures performance stability for each VM.

Memory trick: Keep VMs 'ISOLATED' like separate islands for safety.

A virtual disk type where all the storage space is allocated and reserved on the physical host at the time of its creation, regardless of how much data is initially stored within the VM.

• Allocates full size immediately.
• Offers best performance for disk I/O.
• Consumes more physical storage upfront.

Memory trick: For 'FIXED' performance, fix the size.

Software packages installed within a virtual machine's guest operating system to improve performance, usability, and management.

• Provide optimized drivers for virtual hardware (video, network, storage).
• Enhance communication between guest OS and hypervisor.
• Examples: VMware Tools, Hyper-V Integration Services, VirtualBox Guest Additions.

Memory trick: Tools make the VM run smooth and clear.

The gradual and often unmanaged increase in the CPU, RAM, or storage allocated to or consumed by active virtual machines over time, leading to potential resource contention on the host.

• Gradual increase in VM resource usage.
• Affects active VMs, not just unused ones.
• Can lead to performance degradation on the host.

Memory trick: Resource 'CREEP' is like resources slowly 'CREEPING' up.

A feature in virtualization platforms that automatically detects physical host failures and restarts affected virtual machines on other healthy hosts within a cluster, minimizing downtime.

• Monitors physical host health.
• Automatically restarts VMs on failover.
• Requires shared storage for VMs.

Memory trick: For 'HA'ppy uptime, 'HA've High Availability.

A form of OS-level virtualization that packages an application and all its dependencies (code, runtime, system tools, libraries, settings) into an isolated unit that can run consistently across any environment.

• Share the host OS kernel.
• More lightweight and faster than VMs.
• Ensures application portability and consistency.

Memory trick: VMs are houses, Containers are apartments.

A characteristic of cloud computing that allows computing resources to be provisioned and de-provisioned quickly and automatically, scaling rapidly commensurate with demand.

• Enables dynamic scaling up or down.
• Often automated, without human intervention.
• Key for handling fluctuating workloads.

Memory trick: On-Demand, Broad Network, Resource Pool, Rapid Elasticity, Measured Service.

A lightweight, standalone, executable package of software that includes everything needed to run an application: code, runtime, system tools, system libraries, and settings.

• Shares the host OS kernel.
• Faster to start and more resource-efficient than VMs.
• Ensures consistent application environments across different platforms.

Memory trick: A 'CONTAINER' holds everything neatly for a smooth voyage.

A variation of public cloud where a provider offers infrastructure (servers, network) that is physically dedicated to a single customer, ensuring absolute isolation from other tenants.

• Physically separate hardware for one customer.
• Offers enhanced security and compliance compared to multi-tenant public cloud.
• Managed by a public cloud provider, but resources are not shared.

Memory trick: Public is shared, Private is yours, Dedicated is yours at the provider's.

A server or service in a Virtual Desktop Infrastructure (VDI) environment that authenticates users and assigns them to an available virtual desktop instance.

• Acts as a gatekeeper for user access.
• Manages desktop assignments and load balancing.
• Central to user experience and access control in VDI.

Memory trick: Users Connect to Brokers, Brokers to Desktops on Hypervisors.

A characteristic of cloud computing where resource usage is monitored, controlled, and reported, providing transparency for both the provider and consumer. This enables a 'pay-per-use' or consumption-based billing model.

• Resource usage is tracked and reported.
• Enables transparent billing based on consumption.
• Often aligns with 'pay-as-you-go' models.

Memory trick: To 'MEASURE' your bill, you need 'MEASURED' service.

Assigning an appropriate number of virtual CPUs (vCPUs) to a virtual machine based on its workload requirements to optimize performance.

• Too few vCPUs can bottleneck CPU-bound applications.
• Too many vCPUs can lead to scheduling overhead (vCPU ready time).
• Start with minimal vCPUs and increase as needed, monitoring performance.

Memory trick: More vCPUs for more work, but not too many.

The process of assigning a specific amount of physical RAM from the host machine to a virtual machine.

• Total host RAM must accommodate hypervisor and all running VMs.
• Overcommitment allows allocating more RAM than physically available, but can lead to performance issues.
• Critical VMs should have dedicated, non-overcommitted RAM.

Memory trick: Total minus Hypervisor minus VM equals Remaining.

A cloud infrastructure operated solely for a single organization, which may be managed internally or by a third party and hosted on-premises or off-premises.

• Dedicated resources for one organization.
• Highest level of control, security, and data privacy.
• Compliance with strict regulations often requires a private cloud.

Memory trick: Public, Private, Hybrid, Community: PP H C