Dmg File Means
What is a DMG file?
What does DMG stand for? All Acronyms has a list of 195 DMG definitions. Updated October 2019. Top DMG acronym meaning: Daimler-Motoren-Gesellschaft. Thus 7-Zip is still our first choice for DMG file extraction. But if 7-Zip is unable to open your DMG file or you just want to extract one file from DMG then you can try DMG Extractor since it supports many different DMG formats. In order to open DMG file in DMG extractor click on the Open button in the toolbar.
DMG files are files that are treated like actual hard disks by the Macintosh OS X operating system. These files can be created with Disk Copy, burned to a CD or even mounted as a normal volume on Macintosh computers. They often contain raw blocks of data that are usually compressed for easier file management.
Some .dmg files may be encrypted in addition to being compressed, for added file security. These files are often used by software installers that download applications from the Internet to a user's computer.
- Looking for the definition of DMG? Find out what is the full meaning of DMG on Abbreviations.com! 'Duel Masters Guide' is one option - get in to view more @ The Web's largest and most authoritative acronyms and abbreviations resource.
- Dec 03, 2003 A dmg is a disk image. I think of them as a disk within a disk. If it won't mount it's possible the file is corrupted, or incomplete. Also I think there is a way to not automatically verify dmg files, which will sometimes let you mount dmg's with 'weird behaviors'.
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- A DMG file is a mountable disk image created in macOS. It contains raw block data typically compressed and sometimes encrypted. DMG files are commonly used for macOS software installers that are downloaded from the Internet, which mount a virtual disk on the desktop when opened.
- 7 definitions of DMG. Definition of DMG in Slang/Internet Slang. What does DMG stand for?
Free cache cleaner for mac. The Oracle export and import utility, used by Oracle databases, also uses the .dmg file extension for database dump files that are stored a binary file format.
Dmg File Meaning
Software that will open, convert or fix DMG files
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About File Extension DMG
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If you have additional information about the DMG file format or software that uses files with the DMG suffix, please do get in touch - we would love hearing from you.
So you’re running Linux on your computer, maybe Ubuntu, and you have some files with the .dmg extension. In this guide, we’re going to talk about how to open, mount, extract, and otherwise get your files from these pesky DMG images. You could always just extract the files on a Mac, then transfer them back to your Linux machine. But if you really want to do this on Linux, without having to rely on Mac, here’s how to do it.
What are DMG image files?
Simply put, it’s a kind of image file. But not an image like a jpeg is an image. DMG is Apple’s proprietary disk image format, native to Mac OS X. There are actually a whole bunch of different types, format and options within this format. There are options for encryption, compression, and different kinds of partition schemes, among others. Unfortunately, this can make things pretty confusing when we’re trying to gain access to the data contained in one of these images.
DMG images are typically a kind of Universal Disk Image Format (UDIF), although there are others, namely NDIF and SPARSE. Although the .dmg file extension is usually used, they can also sometimes have an .img extension, or in some cases no extension at all. Their MIME type is application/x-apple-diskimage.
The HFS/HFS+ (Mac OS Extended/Journaled) file system is typically used in DMGs. However, this isn’t always the case. You may also sometimes find FAT and ExFAT files systems, as well as variations on HFS.
Does my system support DMG?
Perhaps the biggest hurdle to overcome when trying to work with DMG files is working with the HFS file system (Mac OS Extended). Linux supports HFS through the “hfs” and “hfsplus” kernel modules.
There’s an easy way to test if your system has these kernel modules. Plug in a USB drive formatted with the Mac OS Extended file system. If your particular distribution doesn’t have the appropriate modules, you will likely get an error message. On Ubuntu, you’ll get a popup window declaring “Ubuntu: Unable to mount
Alternatively, we can see if the kernel module files are present with find:
You can remove them if you confirm you don’t need them anymore.iOS Software Updates - The updates may become useless after you complete the updates. You can remove them to regain space.Xcode Derived Data - For developers, there may be tons of intermediate build information and project index generated by Xcode. They are good-for-nothing.Trash Cleanup - It helps you empty Trash folders of Mac’s internal and external volumes for better performance.iOS Photo Cache - After you sync photos by any iOS devices, there must be some photo caches left on your Mac, which just consume your space.User Downloads - Some downloaded files may become useless. Removing the downloaded attachments can free up more space.Leftovers - Some remnants may still left on your Mac even after the related applications are deleted. Find junk files.
We want to see two files: “hfs.ko” and “hfsplus.ko”. If find doesn’t return these files, your system probably doesn’t support HFS.
You could also try “modinfo”: modinfo hfs and modinfo hfsplus should return something like:
If you get 'modinfo: ERROR: Module hfsplus not found' your system doesn’t have these modules.
Not all Linux kernels and distributions support HFS. This is especially the case for certain distributions that are a few years old. If you have kernel support for HFS, great! If not, don’t worry. There are still ways to extract data from your DMG files. While it’s nice to have the option to mount the images we’re working with, this is really the only functionality we’re losing without having the hfs and hfsplus modules. The two programs we’re going to use later on (P7ZIP and dmg2img) do not require kernel support to function.
What kinds of DMG images can be opened in Linux?
This guide is about how to open, mount, and extract files from read/write, read only, and compressed DMG image files. The following partition schemes have all been tested with the techniques discussed here.
- Apple Partition Map
- CD/DVD (partitioned)
- CD/DVD (partitioned) with ISO data
- Hard disk
- Master Boot Record Partition Map
- No partition map
Opening Dmg In Window
This guide does not cover how to handle sparse disk images (.sparseimage), sparse bundle disk images (.sparsebundle), or CD/DVD masters. DMG images with partition scheme types of “CD/DVD” and “GUID Partition Map” do not appear to work with the techniques described here.
Option 1: Mount the DMG
If the Linux distribution you’re on has HFS support in the kernel (Ubuntu 14.04.1 LTS supports it), it’s pretty easy to just mount the DMG image:
We’re using “sudo” because we need root privileges to mount things. The HFS+ file system type is specified with “-t hfsplus”. The “/mnt” at the end of the command specifies where we’re mounting the image.
Unmount the image with sudo umount /mnt
If you get a wrong fs type message like the one below, it means the DMG file is either of an unsupported type, or it’s compressed. Unsupported images include sparse images, sparse disk bundles, CD/DVD masters, and images with partition schemes of the CD/DVD or GUID Partition Map types.
Use “file” to learn a little more about the image file:
If you get image.dmg: x86boot sector that means it’s probably using a GUID Partition Map and isn’t supported. This isn’t good, however, it’s also not too terribly common.
What’s more common is to see something like this:
If mounting isn’t working, and this is what you’re seeing with “file image.dmg”, then you’re luck!. Our problems are being caused by compression. Linux doesn’t like to mount compressed DMG images. To get around this little obstacle, we’ll use dmg2img (see below).
Option 2: Use dmg2img for compressed images
So you have a DMG image that you can’t mount because it’s compressed. You’ve done “file compressed_image.dmg” and you got “compressed_image.dmg: bzip2 compressed data”. The fix? That’s easy: use dmg2img to convert it to an uncompressed image. Once you run the image through dmg2img you should be able to mount it no problem.
Don’t have dmg2img? It’s usually pretty easy to get using your distribution’s package management. On Ubuntu, you’d do:
Using dmg2img isn’t very difficult. Type “dmg2img” into the command line followed by the name of the DMG file you want to decompress. The Mac OS X version of Firefox is a good example of a compressed DMG file.
Now mount the resulting .img file:
Option 3: Extract DMG contents with P7ZIP
P7ZIP is awesome. It’s the Linux/BSD version of 7-Zip. Check out their SourceForge page here With it you can literally extract files from any kind of image or archive. Just kidding… It doesn’t really work with every format conceivable. However, it can handle (in alphabetical order): ARJ, CAB, CHM, CPIO, CramFS, DEB, DMG, FAT, HFS, ISO, LZH, LZMA, MBR, MSI, NSIS, NTFS, RAR, RPM, SquashFS, UDF, VHD, WIM, XAR and Z. Impressed? I certainly am!
Installing p7zip is pretty easy using your distribution’s package management system. On Ubuntu with apt-get:
In addition to being able to extract data from compressed and uncompressed images alike, P7ZIP doesn’t require the HFS kernel modules at all. In the example below, we’re going to extract all of the files from “Firefox 33.1.1.dmg”. When we’re done, we’ll have a tidy little folder called “Firefox”.
Invoke P7ZIP to extract archives and images with “7z x”.
Notice that 7z extracted three files: “0.ddm”, “1.Apple_partition_map”, and “2.hfs”. To actually get to the files, we’ll need to run 7z again on “2.hfs”.
We picked “2.hfs” because it was the biggest of the three, meaning it was probably the one with the data. Simple but effective logic. After a few moments, you should have a folder called “Firefox” with all of the files from the original DMG.