220-1102 Operating Systems Practice Question
A technician needs to create a bootable USB installer for macOS High Sierra on a Mac computer. Which command-line utility should the technician use?
⚠ Common exam trap
The trap here is that candidates familiar with Windows or Linux might mistakenly choose `dd` or `rufus` because they are common for creating bootable media on other platforms, but macOS has its own dedicated command-line utility (`createinstallmedia`) that must be used for macOS installer creation.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
createinstallmedia
The `createinstallmedia` command is a built-in macOS utility specifically designed to create a bootable installer for macOS. It is located inside the macOS installer app bundle and is the correct tool for creating a bootable USB installer for High Sierra or other macOS versions. This command handles all necessary steps, including erasing the target volume and copying the installer files with the proper boot configuration.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
dd
Why it's wrong here
dd is a low-level byte copy tool in Unix/macOS; while it can copy a macOS installer image (like a .dmg) directly to a USB device, it is not the standard because it doesn't handle the macOS installer's special layout (e.g., the Installer partition, bootable GUID) and may produce an unbootable result. Apple provides createinstallmedia to properly format the volume as Mac OS Extended (Journaled), copy the installer files, and set the bootable flags. So dd is wrong because it's not reliable or recommended.
- ✓
createinstallmedia
Why this is correct
This is the official utility buried inside the "Install macOS High Sierra.app" bundle at /Contents/Resources/createinstallmedia. It erases the USB drive, formats it as Mac OS Extended (Journaled) with a GUID partition table, copies the installer application's contents, and makes the volume bootable. It's the only supported command-line method for building a bootable installer.
- ✗
diskmgmt
Why it's wrong here
diskmgmt.msc is the Windows Disk Management snap-in, not a macOS command. It operates on Windows volumes and cannot create a macOS bootable installer. On macOS, disk management is done with Disk Utility or diskutil, so diskmgmt is entirely inapplicable.
- ✗
rufus
Why it's wrong here
Rufus is a Windows utility for creating bootable USB drives, commonly for installing Windows or Linux. It does not know how to prepare a macOS High Sierra installer because it doesn't understand Apple's file system formats (HFS+/APFS) and lacks the necessary bootstrap code. Even if run under Windows (e.g., with a DMG), it cannot produce a bootable macOS installer for a Mac.
Quick reference
Access Control Model Comparison
| Model | Acronym | Who Controls Access? | Best For |
|---|---|---|---|
| Discretionary Access Control | DAC | Resource owner | Small teams, file shares |
| Mandatory Access Control | MAC | System / security labels | Classified govt / military |
| Role-Based Access Control | RBAC | Administrator (via roles) | Enterprise environments |
| Attribute-Based Access Control | ABAC | Policy engine (user + resource attributes) | Fine-grained, dynamic policies |
| Rule-Based Access Control | RuBAC | System rules / ACLs | Firewall rules, network ACLs |
Go deeper
Related to this question
Learn chapter
macOS System Preferences and Settings
Key term
macOS
macOS is the operating system that powers Apple's Mac computers, providing a graphical interface, system management, and security features for users and IT professionals.
Key term
Universal Serial Bus
A Universal Serial Bus (USB) is a standard interface that allows you to connect devices like keyboards, mice, storage drives, and printers to a computer for data transfer and power delivery.
About these practice questions
This 220-1102 question is part of Courseiva's 925-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on 220-1102
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A user wants to create a bootable macOS installer on a USB flash drive to install macOS on another Mac. Which command-line utility is designed specifically for this purpose in macOS?
easy- A.Disk Utility
- ✓ B.createinstallmedia
- C.dd
- D.rsync
Why B: The `createinstallmedia` command is a built-in macOS utility specifically designed to create a bootable installer from a downloaded macOS installer app. It automates the process of formatting the target volume and copying the necessary system files, ensuring the resulting USB drive is bootable and compatible with the target Mac's firmware.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1102 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 220-1102 exam.