If the disk image will be used with a Mac that has a solid state drive (SSD) and uses macOS 10.13 or later, choose APFS or APFS (Case-sensitive). If the disk image will be used with a Mac with macOS 10.12 or earlier, choose Mac OS Extended (Journaled) or Mac OS Extended (Case-sensitive, Journaled).
The icon represents an internal hard drive within a generic file icon. | |
Filename extension | |
---|---|
Internet media type | application/x-apple-diskimage |
Uniform Type Identifier (UTI) | com.apple.disk-image |
Developed by | Apple Inc. |
Type of format | Disk image |
Apple Disk Image is a disk image format commonly used by the macOS operating system. When opened, an Apple Disk Image is mounted as a volume within the Macintosh Finder.
An Apple Disk Image can be structured according to one of several proprietary disk image formats, including the Universal Disk Image Format (UDIF) from Mac OS X and the New Disk Image Format (NDIF) from Mac OS 9. An Apple disk image file's name usually has '.dmg' as its extension.
- There are also two other ways to do so — the first is by opening up Disk Utility and going to File - Open Disk Image. The second way is by opening up a Terminal window and typing something similar to the following: hdiutil mount filename.iso. Did this really require us to write up a tip?
- Apple Disk Image is a disk image format commonly used by the macOS operating system. When opened, an Apple Disk Image is mounted as a volume within the Macintosh Finder. An Apple Disk Image can be structured according to one of several proprietary disk image formats, including the Universal Disk Image Format (UDIF) from Mac OS X and the New Disk Image Format (NDIF) from Mac OS 9.
Features[edit]
Apple Disk Image files are published with a MIME type of application/x-apple-diskimage.
Different file systems can be contained inside these disk images, and there is also support for creating hybrid optical media images that contain multiple file systems.[1] Some of the file systems supported include Hierarchical File System (HFS), HFS Plus, File Allocation Table (FAT), ISO9660 and Universal Disk Format (UDF).[1][2]
Apple Disk Images can be created using utilities bundled with Mac OS X, specifically Disk Copy in Mac OS X v10.2 and earlier and Disk Utility in Mac OS X v10.3 and later. These utilities can also use Apple disk image files as images for burning CDs and DVDs. Disk image files may also be managed via the command line interface using the hdiutil utility.[3]
In Mac OS X v10.2.3, Apple introduced Compressed Disk Images[4] and Internet-Enabled Disk Images for use with the Apple utility Disk Copy, which was later integrated into Disk Utility in 10.3. The Disk Copy application had the ability to display a multi-lingual software license agreement before mounting a disk image. The image will not be mounted unless the user indicates agreement with the license.[5]
An Apple Disk Image allows secure password protection as well as file compression, and hence serves both security and file distribution functions; such a disk image is most commonly used to distribute software over the Internet.
History[edit]
Apple originally created its disk image formats because the resource fork used by Mac applications could not easily be transferred over mixed networks such as those that make up the Internet. Even as the use of resource forks declined with Mac OS X, disk images remained the standard software distribution format. Disk images allow the distributor to control the Finder's presentation of the window, which is commonly used to instruct the user to copy the application to the correct folder.
Mac Os X Disk Image
A previous version of the format, intended only for floppy disk images, is usually referred to as 'Disk Copy 4.2' format, after the version of the Disk Copy utility that was used to handle these images.[1] A similar format that supported compression of floppy disk images is called DART.[1][6]
New Disk Image Format (NDIF) was the previous default disk image format in Mac OS 9,[1] and disk images with this format generally have a .img (not to be confused with raw .img disk image files) or .smi file extension. Files with the .smi extension are actually applications that mount an embedded disk image, thus a 'Self Mounting Image', intended only for Mac OS 9 and earlier.[7][2]
Universal Disk Image Format (UDIF) is the native disk image format for Mac OS X. Mac os x 10.10 yosemite ver 2015 download mp3. Disk images in this format typically have a .dmg extension.[1]
File format[edit]
Apple has not released any documentation on the format, but attempts to reverse engineer parts of the format have been successful. The encrypted layer was reverse engineered in an implementation called VileFault (a spoonerism of FileVault).[8]
Apple disk image files are essentially raw disk images (i.e. contain block data) with some added metadata, optionally with one or two layers applied that provide compression and encryption. In hdiutil these layers are called CUDIFEncoding and CEncryptedEncoding.[1]
UDIF supports ADC (an old proprietary compression format by Apple), zlib, bzip2 (as of Mac OS X v10.4), and LZFSE (as of Mac OS X v10.11)[9] compression internally.
Metadata[edit]
The UDIF metadata is found at the end of the disk image following the data. This trailer can be described using the following C structure.[10] All values are big-endian (PowerPC byte ordering)
The XML plist contains a
blkx
(blocks) key, with information about how the preceding data fork is allocated. The main data is stored in a base64 block, using tables identified by the magic 'mish'
. This 'mish'
structure contains a table about blocks of data and the position and lengths of each 'chunk' (usually only one chunk, but compression will create more).[10] The data and resource fork information is probably inherited from NDIF.Encryption[edit]
The encryption layer comes in two versions. Version 1 has a trailer at the end of the file, while version 2 (default since OS X 10.5) puts it at the beginning. Whether the encryption is a layer outside of or inside of the
blkx
metadata (UDIF) is unclear from reverse engineered documentation, but judging from the vfcrack
demonstration it's probably outside.[8]Utilities[edit]
There are few options available to extract files or mount the proprietary Apple Disk Image format. Some cross-platform conversion utilities are:
- dmg2img was originally written in Perl; however, the Perl version is no longer maintained, and the project was rewritten in C. It extracts the raw disk image from a DMG, without handling the file system inside. UDIF ADC-compressed images (UDCO) have been supported since version 1.5.[11]
- DMGEXtractor is written in Java with GUI, and it supports more advanced features of dmg including AES-128 encrypted images but not UDCO images.[12]
- The Sleuth Kit. Handles the DMG format, HFS+, and APFS.
Most dmg files are unencrypted. Because the dmg metadata is found in the end, a program not understanding dmg files can nevertheless read it as if it was a normal disk image, as long as there is support for the file system inside. Tools with this sort of capacity include:
- Cross-platform: 7-zip (HFS/HFS+), PeaZip (HFS/HFS+).
- Windows: UltraISO, IsoBuster, MacDrive (HFS/HFS+).[13]
- Unix-like: cdrecord and
mount
(e.g.mount -o loop,ro -t hfsplus imagefile.dmg /mnt/mountpoint
).[14][15]
Tools with specific dmg support include:
- Windows:
- Transmac can handle both UDIF dmgs and sparsebundles, as well as HFS/HFS+ and APFS. It is unknown whether it handles encryption.[16] It can be used to create bootable macOS installers under Windows.[17]
- A free Apple DMG Disk Image Viewer also exists, but it is unknown how much what it actually supports.[18].
- Unix-like:
- darling-dmg is a FUSE module enabling easy DMG file mounting on Linux. It supports UDIF and HFS/HFS+.[19]
See also[edit]
References[edit]
- ^ abcdefg'hdiutil(1) Mac OS X Manual Page'. Archived from the original on 2016-05-14. Retrieved 2016-05-14.
- ^ ab'Mac OS X: Using Disk Copy disk image files'. Archived from the original on 2013-12-19. Retrieved 2013-04-25.
- ^
hdiutil(1)
– Darwin and macOS General Commands Manual - ^'Re: Some apps refuse to launch in 10.2.8! (OT, but very important)'. Archived from the original on 2014-01-17.
- ^'Guides'. Apple. Archived from the original on 2009-03-06. Retrieved 2010-10-27.
- ^'DART 1.5.3: Version Change History'. Archived from the original on 2013-12-19. Retrieved 2013-04-25.
- ^'Software Downloads: Formats and Common Error Messages'. Archived from the original on 2010-12-24. Retrieved 2009-05-06.
- ^ ab'VileFault'. 2006-12-29. Archived from the original on 2007-01-09. Retrieved 2010-10-27.
- ^Michael Tsai (2015-10-07). 'LZFSE Disk Images in El Capitan'. Archived from the original on 2017-04-09. Retrieved 2017-04-09.
- ^ ab'Demystifying the DMG File Format'. Archived from the original on 2013-03-17.
- ^'dmg2img'. Archived from the original on 29 November 2010. Retrieved 2010-10-27.
- ^'DMGExtractor'. Archived from the original on 2011-01-02. Retrieved 2011-01-03.
- ^MacDrive Features / Boot Camp / System Requirements /. 'MacDrive Home page'. Mediafour. Archived from the original on 4 October 2010. Retrieved 2010-10-27.
- ^'How To Convert DMG To ISO in Windows, Linux & Mac'. Archived from the original on 2010-03-07.
- ^'Convert DMG To ISO using PowerISO'. Archived from the original on 2009-05-02. Retrieved 2009-02-15.
- ^'About TransMac for Windows'. www.acutesystems.com.
- ^'Convert'. www.winytips.com. winytips. Retrieved 5 May 2020.
- ^Olivia Dehaviland (2015-03-03). 'Apple DMG Disk Image Viewer'. DataForensics.org. Archived from the original on 2015-04-02. Retrieved 2015-03-10.
- ^'darling-dmg'. darling-dmg. Retrieved 29 March 2015.
External links[edit]
- Apple Developer Connection A Quick Look at PackageMaker and Installer
- O'Reilly Mac DevCenter Tip 16-5. Create a Disk Image from a Directory in the Terminal
Retrieved from 'https://en.wikipedia.org/w/index.php?title=Apple_Disk_Image&oldid=974640450'
Summary
When a hard drive becomes raw, you cannot access pictures, videos, office files and music from macOS. EaseUS Data Recovery Wizard for Mac is the best software for Mac Raw recovery. This easy-to-use software only takes three steps to restore lost Raw data. Read on to learn the detailed steps.
PAGE CONTENT:
- Use Mac RAW recovery software to recover data from RAW drive
- How to fix RAW partition on Mac
- FAQs about Mac RAW hard drive data recovery
Symptoms of Raw Drive/Partition on Mac
A hard drive that displays files as RAW means the Mac cannot properly read it as they drive may have become corrupted. The RAW file system is a system error due to virus infection, power outages, format failure, or improper system shut down. Generally, when the hard drive is shown as RAW, possible symptoms are:
- The file system is displayed as 'RAW'
- File names contain 'weird' characters.
- When you access files, it will warn 'Sector not found'
- You will be reminded of 'Disk is not formatted. Do you want to format now?'
Usually, the effective way to fix the RAW partition is to erase and format the drive with a new file system by rebuilding DBR, FAT, MFT, etc., so that RAW partition can be accessed and used again.
But as we all know, hard drive formatting will lead to data loss. Therefore, you need to first recover your essential data from the RAW drive with a professional Mac RAW recovery tool. After that, continue fixing the RAW disk by formatting.
The Solution for Mac RAW Data Recovery
Before you do anything to the drive, if the data on the hard drive is important or irreplaceable, it's best to stop using it immediately and turn to specialized RAW recovery software to get back the files in advance.
A wide range of supported file systems and availability of different scanning modes make EaseUS Data Recovery Wizard for Mac the best Mac data recovery software. With it, you can recover data from Mac hard drive, external drive, memory card, as well as recover deleted files from trash.
The software is easy-to-use and safe. You can completely trust it as it has so many users around the world. With simple 3 steps, you can restore all lost files from hard drive on Mac 10.15, 10.14, 10.13, 10.12, or below. Read on to recover RAW data on Mac.
Step 1. Select the disk location (it can be an internal HDD/SSD or a removable storage device) where you lost data and files. Click the Scan button.
Step 2. EaseUS Data Recovery Wizard for Mac will immediately scan your selected disk volume and display the scanning results on the left pane.
Step 3. In the scan results, select the file(s) and click Recover Now button to have them back.
Mac Os X Mount Raw Disk Images
Also read: Mac partition recovery: how to recover deleted or lost partition on macOS/Mac OS X
How to Fix Mac RAW Partition by Formatting
Now that you've successfully recovered files from RAW disk with EaseUS Mac RAW recovery program, you can try to repair the corrupted RAW partition. To fix a RAW disk, you can format it to any supported files system on Mac, including APFS, HFS+, HFS X, FAT16, FAT32, exFAT, and NTFS.
In this section, we will show you two ways to format the RAW file system to NTFS/FAT32 with ease. The solutions are applicable to format a RAW drive on HDD, USB, SD card, or memory card.
1. Format RAW Partition with Disk Utility
Step 1. Go to 'Applications' > 'Utilities' > Double click and open 'Disk Utility'.
Step 2. Select your RAW drive or other USB flash drives on the sidebar, choose'Erase'.
Step 3. Rename the RAW partition, choose the format as MS-DOS (FAT) for Format, Master Boot Record for Scheme. Then click 'Erase'.
Digital performer 9 mac torrent. Wait for the process to complete, then you'll get an empty new hard drive with FAT32 as the file system. You can reuse the partition for saving data again.
2. Format RAW Drive on Mac with Terminal Command Line
Another more complicated way to fix and format a RAW partition is using the Terminal command line. If you are a novice to Mac computer, you'd better use the Disk Utility to complete the formatting with simple clicks.
Step 1. Hit cmd + space to run Spotlight, type: terminal, and hit Enter.
Step 2. Type:diskutil list and find out the corrupted RAW drive.
Step 3. Type: sudo diskutil eraseDisk FAT32 MBRFormat /dev/disk2.
- sudo gives you user right
- Diskutil calls disk utility program
- eraseDisk commands to format
- FAT32 sets the file system
- MBRFormat tells disk utility to format with a Master Boot Record
- /dev/disk2 is the location of an external hard drive
Step 4. Wait for the process to complete. After this, you can type: diskutil list in command again to check if the formatting has been successful.
Macos Mount Raw Disk Image
Conclusion
If you want to recover corrupted RAW files from a digital camera, SD card, or hard drive on Mac, EaseUS Mac RAW recovery software is a great choice. It is a professional and easy-to-use RAW file recovery tool. Format factory windows 10. Besides, the software is also qualified to fix corrupted photos and repair corrupted MOV/MP4 files on Mac.
Instead of data recovery after hard drive corruption, avoiding RAW drive again and being at risk of data loss in advance is more useful. You can pay attention to the following points in the daily use of a computer:
- Install and upgrade the antivirus software
- Safely eject the external USB drive
- Avoid misoperation, such as sudden power outage
- Use the advanced file system, like NTFS
- Back up important data regularly
FAQs About Mac Raw Hard Drive Data Recovery
Here are the frequently asked questions related to RAW recovery for Mac. If you also have any of these problems, you can find the methods here.
What is raw drive recovery?
Mac Raw recovery is a type of data recovery. When the hard drive is crashed, or the file system has been damaged, raw recovery can help users recover most of the lost files on a hard drive, SD card, USB flash drive, or other storage media devices.
How do I restore raw disk?
Use EaseUS Data Recovery Wizard for Mac to restore RAW disk within three steps:
Step 1. Select the RAW hard drive where you lost data and files. Click the Scan button.
Step 2. EaseUS Mac RAW recovery software will immediately scan your selected disk volume and display the scanning results on the left pane.
Step 3. In the scan results, select the file(s) and click Recover Now button to have them back.
Is Mac Data Recovery Free?
The free version of EaseUS Data Recovery Wizard for Mac lets you recover up to 2 GB of data free of charge. It enables you to recover deleted or lost photos, videos, Word, Excel, PPT, and other files from all Mac devices and external storage media, like external HDD/SSD, fusion drive, USB drive, SD card, CF card, Digital Camera, Video Player, and more.
What is the best data recovery software for Mac?
One of the best data recovery software for Mac is EaseUS Data Recovery Wizard. It can help you restore data in complex cases by supporting deleted file recovery, formatted recovery, RAW recovery, partition recovery, virus attack recovery, OS crash recovery, and other recovery scenarios.
Other best data recovery software for Mac you can try is:
- Disk Drill
- PhotoRec
- TestDisk
- Exif Untrasher