CompTIA A+ Core 2 Operating Systems Questions

Correct Answer: Check systemctl dependencies with systemctl list-dependencies.
Explanation: A "dependency failed" error indicates a missing or failed dependent service. Using systemctl list-dependencies identifies the issue for targeted troubleshooting. Restarting is ineffective, reinstalling is premature, journal flushing is irrelevant, and ignoring dependencies risks instability.

Correct Answer: Edit Group Policy to restrict RDP access to the security group.
Explanation: Group Policy (e.g., via gpedit.msc) allows precise control over RDP access by specifying allowed groups, ensuring security. The Remote Desktop Users group is less granular, firewalls can’t filter by group, PowerShell is less standard, and registry edits are riskier.

Correct Answer: Temporary files accumulation; clean them with Disk Cleanup.
Explanation: Low disk space warnings can result from temporary files (e.g., Windows Update cache) consuming space. Disk Cleanup is the safest fix. System Reserved or recovery partitions rarely trigger this, quotas are user-specific, and filesystem corruption would show different symptoms.

Correct Answer: Missing execute permission; add it using chmod +x script.sh.
Explanation: Scripts require execute permission to run, which isn’t granted by read/write permissions. Using chmod +x adds it. SELinux could be an issue but is less common, shebang issues cause different errors, noexec mounts are rare, and sudoers is irrelevant for non-privileged scripts.

Correct Answer: Modify System Preferences to allow the app under Security & Privacy.
Explanation: macOS Gatekeeper prompts allow users to permit unverified apps in System Preferences > Security & Privacy, which is the most secure and user-friendly method. spctl --add is complex, disabling Gatekeeper is risky, xattr -d removes quarantine but is less intuitive, and re-downloading may not be possible.

Correct Answer: Outdated Wi-Fi driver; update the driver via Device Manager.
Explanation: Post-update connectivity issues often stem from outdated or incompatible drivers. Updating the Wi-Fi driver is the most direct fix. DHCP issues would show different errors, DNS settings are secondary, firewall issues are unlikely, and resetting the network stack is a broader fix.

Correct Answer: Use cron to schedule an rsync command to the remote server.
Explanation: cron is the standard tool for scheduling recurring tasks, and rsync is efficient for remote backups, ensuring only changed files are transferred. systemd timers are more complex, anacron is for non-continuous systems, at is for one-time tasks, and rclone is less common than rsync for this purpose.

Correct Answer: Use Resource Monitor to identify the specific service causing high I/O.
Explanation: svchost.exe hosts multiple services, and Resource Monitor can pinpoint which service is causing high disk I/O for targeted troubleshooting. Restarting services is premature, sfc /scannow addresses corruption not I/O, virtual memory tweaks are secondary, and disabling updates is risky and unrelated.

Correct Answer: Install Windows first, then Ubuntu, and let GRUB configure the boot order.
Explanation: Installing Windows first allows Ubuntu’s GRUB bootloader to detect and configure both OSes in the EFI boot order, ensuring compatibility. Installing Ubuntu first risks Windows overwriting GRUB. Separate EFI partitions are unnecessary, disabling Secure Boot may not be required, and bcdedit is less reliable for Linux.

Correct Answer: Delete Time Machine snapshots using tmutil to reclaim space.
Explanation: Time Machine snapshots often consume significant APFS space, preventing updates. Using tmutil to delete them is a targeted, non-destructive solution. Resizing containers is complex, purge clears minimal cache, reinstalling macOS is overkill, and iCloud offloading may not free enough space.

Correct Answer: Incorrect SMB credentials; verify and update credentials in Windows Credential Manager.
Explanation: "Access denied" typically indicates incorrect credentials. Updating them in Windows Credential Manager resolves the issue. SMBv1 is deprecated and unlikely, NTFS permissions don’t apply to Linux, firewall issues would show different errors, and guest access is less secure and not the primary cause.

Correct Answer: Configure BitLocker with a startup key on a USB drive.
Explanation: Without a TPM, BitLocker requires an external startup key (e.g., on a USB drive) for secure encryption, as it ensures physical possession for unlocking. A password alone is less secure, installing a TPM is unnecessary, EFS is file-based and not equivalent, and a PIN via Group Policy is less secure than a USB key.

Correct Answer: Execute htop to view processes and select the process to terminate.
Explanation: htop provides an interactive, detailed view of processes with CPU usage and allows termination via a menu, making it ideal for this scenario. top is less user-friendly, ps requires additional steps, system-monitor is GUI-based and not standard on servers, and lsof is for file handles, not CPU usage.

Correct Answer: Configure Time Machine to use the NFS share via a custom sparsebundle.
Explanation: Time Machine supports NFS shares, but they require a sparsebundle image for compatibility, created manually and mounted before selection. Direct NFS selection isn’t supported, AFP is deprecated, rsync bypasses Time Machine, and SMB is less reliable for this purpose.

Correct Answer: Boot into Safe Mode and roll back the driver using Device Manager.
Explanation: A driver-related BSOD is best addressed by booting into Safe Mode, which loads minimal drivers, and rolling back the problematic driver. This is the least invasive initial step. Startup Repair may not address driver issues, BCD rebuilding is irrelevant, System Restore is a broader fix, and resetting the PC risks data loss.

Correct Answer: Modify /etc/ssh/sshd_config with AllowGroups directive; restart the SSH service.
Explanation: The AllowGroups directive in /etc/ssh/sshd_config is the most secure and efficient way to restrict SSH access to a specific group, followed by restarting the SSH service (e.g., systemctl restart sshd). The other options are less effective: /etc/passwd doesn’t control SSH access, iptables cannot filter by group, PAM is overly complex for this, and cron jobs are inefficient and reactive.

Correct Answer: Incorrect DNS configuration; resolve by setting the domain controller as the primary DNS server.
Explanation: GPOs rely on DNS to locate domain controllers. If the client’s DNS is misconfigured, it cannot resolve the domain controller, preventing GPO application. Setting the domain controller as the primary DNS resolves this. The other options are plausible but incorrect: GPO inheritance issues would still show some policies, gpupdate refreshes but doesn’t fix DNS, elevating user permissions is unnecessary, and SMB is unrelated to GPO application.

Correct Answer: Legacy BIOS mode conflicts; resolve by enabling UEFI in firmware settings.
Explanation: Windows 11 requires UEFI for zero-touch deployments due to its secure boot and TPM 2.0 requirements. Legacy BIOS mode on older hardware causes boot failures, which can be resolved by enabling UEFI in the firmware. The second option is plausible but less likely, as TPM issues would typically cause different errors. The third option is incorrect as MBR-to-GPT conversion is secondary to UEFI. The fourth and fifth options misattribute the issue to network or image problems, which are less relevant here.

Correct Answer: XFS's allocation group structure; mitigate by optimizing with larger stripe sizes.
Explanation: XFS uses allocation groups for parallel I/O, but misalignment with hardware (e.g., RAID stripes) can degrade performance under heavy writes. Mitigation involves tuning stripe sizes during formatting or mount options. The first option is incorrect as XFS journaling is efficient, and ReFS is Windows-specific. The third option is wrong as snapshots are unrelated to write performance. The fourth and fifth options are plausible but incorrect, as checksums and fragmentation are not the primary issues here.

Correct Answer: APFS requires a third-party driver on Windows for read/write access.
Explanation: Apple File System (APFS) is designed for macOS and iOS/iPadOS, and Windows lacks native support for it. A third-party driver (e.g., Paragon APFS for Windows) is needed for read/write access. The second option is incorrect as Windows does not support APFS natively, even in read-only mode. The third and fourth options misattribute the issue to vendor limitations or encryption conflicts, though FileVault could complicate matters. The fifth option is incorrect as reformatting to exFAT would erase data and isn't required for access.