DMG is a file of Apple Disk Image. The Apple Disk Images are disk image files commonly used by the Mac OS X operating system. When opened, an Apple disk image is 'mounted' as a volume within the Finder. Several Apple proprietary disk image formats can be used to create these images, including the Universal Disk Image Format (UDIF) and the New Disk Image Format (NDIF). Apple disk images usually have the .dmg file extension.
Jun 20, 2016 LZFSE. This is a reference C implementation of the LZFSE compressor introduced in the Compression library with OS X 10.11 and iOS 9. LZFSE is a Lempel-Ziv style data compression algorithm using Finite State Entropy coding. DMG file is a compressed file format being used widely on Mac computer. Windows OS doesn't natively support DMG disk image files, so if you need to create a bootable USB drive from a DMG file, mostly for bootable Mac OS X or macOS installation USB, you need a special utility to help you complete the task. Aug 02, 2016 Make A Bootable Mac DMG USB With TransMac! Thanks For Watching! As Always if you liked this video, don't forget to Subscribe! Get Cheap Games at G2A Link Bel.
Apple disk images allow secure password protection as well as file compression and hence serves both security and file distribution functions; they are most commonly used to distribute software over the Internet.
Universal Disk Image Format (UDIF) is the native disk image format for Mac OS X. Disk images in this format typically have a .dmg extension. New Disk Image Format (NDIF) was the previous default disk image format in Mac OS 9, 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', and are intended only for Mac OS 9 and earlier. 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. A similar format that supported compression of floppy disk images is called DART. 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. Some of the file systems supported include Hierarchical File System (HFS), HFS Plus, File Allocation Table (FAT), ISO9660 and Universal Disk Format (UDF).
Open/Extract DMG File on Windows
Easy 7-Zip opens/extracts DMG file easily on Windows. The Easy 7-Zip was developed based on 7-Zip. 7-Zip is a famous open source file archiver. The Easy 7-Zip is an easy-to-use version of 7-Zip. The open source freeware keeps all features of 7-Zip and adds a few useful features that makes the software more user-friendly.
Easy 7-Zip works on Windows 10/8.1/8/7/Vista/2008/2003/XP/2000 (both 32-bit and 64-bit compatible).
- Free Download Easy 7-Zip
- Install Easy 7-Zip by step-by-step instructions
- The installation will associate DMG with Easy 7-Zip automatically
- Double-click on DMG file to open DMG file with Easy 7-Zip
- Alternatively, Right-click on DMG file on Windows Explorer
- Done
You will see files or folders within the DMG file then, click button Extract to extract the DMG file.
And then, choose Extract files..., Extract Here, or Extract to 'folder' to extract the DMG file.
Easy 7-Zip Download Links:
You can install and use other alternative freeware that opens/extracts DMG file without burning the DMG file to disc. For example:
- Free DMG Extractor
- HFSExplorer
- PeaZip
Open/Extract DMG File on Mac
B1 Free Archiver opens/extracts DMG file on Mac. B1 Free Archiver is a free software for creating archive folder and extracting archive file. B1 Archiver works on all platforms - Windows, Linux, Mac and Android. The freeware supports most popular formats including DMG.
B1 Free Archiver is compatible with:
- Mac OS X 10.9 Mavericks
- Mac OS X 10.8 Mountain Lion
- Mac OS X 10.7 Lion
- Mac OS X 10.6 Snow Leopard
Alternative freeware that opens/extracts DMG file on Mac.
- Apple Disk Utility
- Keka
- GUI Tar
Open/Extract DMG File on Linux
You can use command mount to mount DMG file as a virtual drive.
First, you must login as a root user, and then create a directory for DMG image
| # mkdir -p /mnt/macimage |
Use mount command as follows to mount DMG file called image.dmg:
| # mount -o loop -t hfsplus image.dmg /mnt/macimage |
If the DMG is HFS file system, use:
| # mount -o loop -t hfs image.dmg /mnt/macimage |
Change directory to list files stored inside an DMG image:
| # cd /mnt/macimage # ls -l |
Unmount the DMG image, type:
| # umount /mnt/macimage |
Alternatively, you can use p7zip to extract the DMG file. p7zip is the Unix command-line port of 7-Zip, a file archiver that archives with high compression ratios.
Install p7zip-full on CentOS and Fedora
| # yum install p7zip-full |
Install p7zip-full on Debian and Ubuntu
Dmg Images With Lzfse Compression Are Not Supported Transmac Video
| $ sudo apt-get install p7zip-full |
List directories and files in DMG file
| $ 7z l image.dmg |
Extract DMG file on Linux
| $ 7z x image.dmg |
One of my favorite improvements in El Capitan is the new LZFSE compression algorithm, which is available directly to apps as well as via a new disk image format. The new .dmg format is not accessible in Disk Utility, but I’ve added support for it in DropDMG 3.2.8. Here are some benchmarks I made imaging a 11.28 GB boot partition on a MacBook Air.
| Method | Size | Savings | Throughput |
|---|---|---|---|
| zlib (10.10) | 8.86 GB | 21.4% | 63.5 MB/sec |
| zlib (10.11) | 8.75 GB | 22.3% | 36.8 MB/sec |
| LZFSE (10.11) | 8.60 GB | 23.8% | 107.7 MB/sec |
| bzip2 (10.11) | 7.03 GB* | 23.2% | 11.7 MB/sec |
| none (10.11) | 9.15 GB* | 0% | 114.4 MB/sec |
The source and destination partitions were on the same SSD, and both were encrypted with FileVault 2. I’m impressed that the Air can decrypt, compress, and encrypt to the same drive at more than 100 MB/sec. In 1996, I measured copy throughput at just 43K/sec.
The bottom line is that LZFSE is both faster than zlib and compresses more tightly. (It is supposed to decompress faster as well.) Apple has also tweaked the way zlib is used so that disk images created on 10.11 are smaller than those created on 10.10 (but are slower to create). The smaller zlib disk images are still backwards compatible with previous OS versions, whereas the LZFSE disk images can only be opened on 10.11 or later.
Lastly, the redesigned Disk Utility has removed the feature for burning disk images. The help claims that you can do this with the Finder, but I think that feature has also been removed. You can still burn files and disk images with DropDMG.
Update (2015-10-07): The Burn command is still in the Finder, but now it’s only shown if a burner is connected.
I added results for bzip2 and none (no compression). The destination sizes say * because I no longer have the exact same volume (an El Capitan beta) to test with; I instead imaged a fresh El Capitan installation, which had a different source size (9.15 GB) but should be a similar mix of files. These new results show that bzip2 is really slow, which was common knowledge. More interestingly, no compression was not much faster than LZFSE (which makes sense given LZFSE’s goals), and bzip2 was actually worse at compressing than LZFSE (unexpected).
How does bzip2 compare?
'LZFSE is only present in iOS and OS X, so it can’t be used when the compressed payload has to be shared to other platforms (Linux, Windows). In all other cases, LZFSE is recommended as a replacement for ZLIB.'
A proprietary compression, not that exciting really, as I can't really come up with too many 'other cases'.
bzip2 uses Huffman (instead of FSE) which doesn't handle skewed probability distributions - it is probably the reason of weaker compression.
While LZFSE is a propriety software, ZSTD is an open source LZ+FSE: https://github.com/Cyan4973/zstd
Dmg Images With Lzfse Compression Are Not Supported Transmac For Mac
Your test file is nearly incompressible.
Better use a more typical compressible file where the savings are from 80% to 65%.
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