Sudo dd bs=1m if=$SRC | sudo dd bs=1m of=$DST # Notice how similar this is to doing a simple Sudo dd bs=1m if=$SRC | pv | sudo dd bs=1m of=$DST # I'm going to define variables to make your copy-paste easier

The dd function listens for control-t key and will update you on progress when it is asked to report while running. This allows you to use unix pipes in between. The command to copy it is going to be very similar to common dd commands except we are going to take advantage of the fact that of (output file) defaults to STDOUT and if (input file) defaults to STDIN. In this case /dev/disk2 is an Micro SD card from my Raspberry Pi in the internal reader and /dev/disk3 is a new MicroSD in a USB dongle. diskutil listĢ: Apple_CoreStorage SSD 250.1 GB disk0s2ġ: Windows_FAT_32 NO NAME 15.6 GB disk3s1 Then decide which disks you want to copy. If you are using homebrew (and you should be) installing pv is as easy as: brew install pv If you install pv (pipe viewer) you can use it to monitor the progress of any stream. The disk structure is copied block-by-block so this dd approach works to copy data from a disk that uses a partitioning scheme that macOS doesn't natively support.Ĭopying even a small disk can take a long time and the silence can be frustrating. Reboot your system using the Macintosh HD drive and enjoy your clone! And when we say bit-wise perfect we mean it.

Now you've got a bit-wise perfect clone of your Macintosh HD drive. The last block written was a short block because there wasn't a full 1MB block to copy. That last error message is actually okay. When dd finishes you may see an error like this: dd: /dev/rdisk2: short write on character deviceĥ00107862016 bytes transferred in 14584.393113 secs (34290619 bytes/sec) Start the clone with: > sudo dd if=/dev/rdisk0 of=/dev/rdisk2 bs=1m conv=noerror,sync Let's say that Macintosh HD (disk0) is the source and Clone (disk2) is the target for our dd operation. For example: > diskutil listĢ: Apple_HFS Macintosh HD 319.2 GB disk0s2ģ: Apple_Boot Recovery HD 650.0 MB disk0s3 One of them will be your target drive you're trying to clone. Run diskutil to get a list of your available drives. With your machine booted to your secondary boot disk, log in and fire up a Terminal or iTerm window. Otherwise you risk copying things that are in incomplete states on disk. Your source for the clone should be an offline volume, not in use, when you're making the copy. To prepare for the clone I recommend creating a secondary boot disk that you can boot from. In order to make the clone perfect you'll need to ensure the source and the destination aren't actively in use. It's a command line tool that ships with OS X.

You can use the dd command to make a bit-perfect clone of a drive.

Copy mac hard drive