You can use 'Disk Utility' GUI tool to create and restore images. $ sudo sh -c 'gunzip -c .gz | dd of=/dev/disk2' # Restores compressed image and write /dev/disk2 # $ file : x86 boot sector partition 1: ID=0xc, starthead 130, startsector 8192, 114688 sectors partition 2: ID=0x83, starthead 165, startsector 122880, 6277120 sectors, code offset 0xb8 How do I write dd images to disk again? You can verify your disk with file command: gzip -c > .gz : Create compressed disk image using gzip.With it, you can also restore a Time Machine backup, reset an administrator password, perform disk maintenance, and fix lots of different problens. bs=64k or bs=1m or bs=512 : Set both input and output block size to n bytes. There is a lot to explore in this mode besides the function of reinstalling the operating system (macOS).$ sudo dd if=/dev/disk2 bs=64K | gzip -c > .gz You can create compressed disk image as follows: You can press the ctrl+ t (hold control key and press t) to see dd command progress on macOS: Password:ģ965190144 bytes transferred in 839.664927 secs (4722348 bytes/sec) It will take some time, and you won’t see any updates on the screen. $ sudo dd if=/dev/disk2 of=backup.my. bs=1m

$ sudo dd if=/dev/disk2 of=backup.my. bs=512 Create the disk image with ddįinally create the disk image of the entire disk /dev/disk2: Here is what we see: Unmount of all volumes on disk2 was successful 3. In this example my SD card size is 4GB and located at /dev/disk2.

Open the Terminal application and type the following command to list disks:įig.01: Insert in your SD card, or USB pen/HDD, and see /dev/diskN name To write the disk image: dd if=image.dd of=/dev/DISK.To create the disk image: dd if=/dev/DISK of=image.dd bs=512.How To Create Disk Image on Mac OS X With dd Command Always keep verified backups for your Mac. WARNING: Please be careful when running the following commands, as you might destroy essential data or disk. You also need to use diskutil command manipulates the structure of local disks including listing and unmouting disks before you create or write images to disk. Create new disk images from USB or SD card Connect the USB flash drive with at least 8 Gigabytes storage space to your Mac.

Create mac recovery disk