The current file inside /tmp/ is a read/write image. To convert it into a compressed, read-only DMG file ideal for storage and distribution, execute:
Unmount the newly created volume safely before converting it. hdiutil detach /Volumes/Install\ macOS\ Big\ Sur Use code with caution. Step 5: Convert to a Final Read-Only DMG
Early versions of the Big Sur installer were notorious for failing to check for sufficient disk space macos big sur 1121 installer dmg
: Improved general stability for then-new Apple Silicon (M1) Macs. 💾 Installer DMG Details Size : Approximately 12.2 GB .
Always avoid unverified DMG files from third-party download sites. Security and stability should be your top priorities. By following the official, transparent, and step-by-step guide above, you ensure that your macOS Big Sur 11.2.1 is exactly what it should be: a clean, legitimate, and perfectly functioning copy of Apple's groundbreaking operating system. The current file inside /tmp/ is a read/write image
Alternatively, if you still have the .app file, it is faster to skip the DMG step entirely for USB drives and target your external volume directly:
Ensure you have the exact build required to fix the 2016/2017 MacBook Pro battery charging defect. Step 1: Check System Compatibility Step 5: Convert to a Final Read-Only DMG
hdiutil attach /tmp/BigSur.dmg -noverify -mountpoint /Volumes/BigSur Use code with caution. 3. Write the Installer Files to the Image
codesign --verify --verbose /Applications/Install\ macOS\ Big\ Sur.app
hdiutil create -o /tmp/MacOSBigSur -size 16500m -volname MacOSBigSur -layout SPUD -fs HFS+J hdiutil attach /tmp/MacOSBigSur.dmg -noverify -mountpoint /Volumes/MacOSBigSur sudo /Applications/Install\ macOS\ Big\ Sur.app/Contents/Resources/createinstallmedia --volume /Volumes/MacOSBigSur --nointeraction hdiutil detach /Volumes/MacOSBigSur/ mv /tmp/MacOSBigSur.dmg ~/Desktop/
: Open Terminal (found in /Applications/Utilities/ ).