Plain read/write (UDRW), sparse image (UDSP), and sparse bundle (UDSB) compared for storage efficiency, performance, and convenience.
hdiutil
All you need to know about the sparse RAW disk images used inside lightweight VMs on Apple silicon Macs.
In Monterey and Ventura, regular read-write UDRW disk images can now be APFS sparse files, and work more efficiently than sparse images or sparse bundles.
Disk images originated in the 1960s, and are still valuable tools in modern macOS. They have their limitations, though, and in some cases should be replaced by APFS volumes.
They have more options than most new cars. What are they, how do you use them, how to pick the most appropriate, and which tools to use.
So many different types, from read-only disk image .dmg files, to sparse bundles and DVD/CD-R masters. Which to use, and how to create them?
Disk Utility can’t image APFS volumes, and normally returns an error if you try to image a container. Here’s the workaround.
Important update for all users, which addresses several bugs in setting the maximum size of sparse bundles.
How to set the total size, and band size, for your sparse bundles, with calculation of the critical band size.
Saves you from having to learn how to use hdiutil, and supports 6 different file systems and custom band sizes.
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