Read/write 'sparseimage' disk imagesĪ sparseimage disk image is a type of read/write disk image that grows as you copy files to it. from the Destination selector and locate your disk image. To back up to an existing disk image, select Choose disk image. If you want a read-only disk image for archival purposes, set the image format to one of the read-only formats. If you plan to back up to this disk image again in the future, set the image format to one of the read/write formats.Provide a name and choose a location to save your disk image.Choose your source volume from the Source selector.

In most cases, however, disk images are not a great choice for your backup strategy. If you're backing up to a network volume and your Mac and the NAS device are connected to the network via ethernet, then a disk image may be a good fit. We recommend using disk images sparingly. When you want to access the contents of that filesystem, you double-click on the disk image to mount the disk image as if it were an external drive attached to the machine. We recommend that you only use a disk image if you are backing up to a network volume connected to via ethernet, and we recommend using locally-attached storage for your primary backups.Ī disk image is a single file residing on your hard drive that contains the entire contents of another hard drive (except for the free space). To create a bootable backup, you must back up to a hard drive that is attached directly to your Mac.

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