This is more of a personal note regarding the hdiutil tool.

• To create a sparse image:

$ hdiutil create NAME -volname NAME -type SPARSE -fs hfs+j

• To mount the drive:

$ hdiutil attach NAME.sparseimage

• To add data to the drive:

$ mv data.txt /Volumes/NAME

• To unmount the drive:

$ hdiutil detach /Volumes/NAME

Then, if we delete the NAME.sparseimage file, it’s gone forever and ever.