If the disk image will be used with a Mac or Windows computer and is 32 GB or less, choose MS-DOS (FAT) if it’s over 32 GB, choose ExFAT. 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). 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).

In the Size field, enter a size for the disk image.Ĭlick the Format pop-up menu, then choose the format for the disk:

This is the name that appears on your desktop and in the Finder sidebar, after you open the disk image. In the Name field, enter the name for the disk image. This is the name that appears in the Finder, where you save the disk image file before opening it. In the Disk Utility app on your Mac, choose File > New Image > Blank Image.Įnter a filename for the disk image, add tags if necessary, then choose where to save it. If you need will need to modify or add more data to the disk image, use the parameter -format UDRW which represents read/write.Ĭombining all of the above, the command would be: hdiutil create ~/Desktop/newimage.You can create an empty disk image, add data to it, then use it to create disks, CDs, or DVDs. The parameter -size can be used to specify the size of the disk image to create. Standard disk images cannot increase in size, so you'll need to specify a particular size if you intend to be adding data to it later. So if I mount this new disk image, you'll see OS X mounts it as 'New Disk Image'.ĭisk images generated using the above methods are read-only and formatted as HFS+ by default, though their size will be just enough to contain all the data needed. When the image is mounted or restored to a disk, the volume name is what's referred to. The name of the disk image and volume name are two different things, the first simply refers to the filename of the disk image created. Using the above command, we could perform the following: hdiutil create ~/Desktop/newimage.dmg -volname 'New Disk Image' -srcfolder ~/Desktop/myfolder The hdiutil command can also be used to create a disk image based upon a folder. its tough being 20 yr old silicon valley techy ) well heres an answer acceptable in their 'format.' i guess i wont get back the little reputation i received that the admin stripped me from. Apparently my last answer doesn't fit the criteria of the moderator.

How to copy a mac disk image