Or, if you can concurrently attach both disks, copy directly: sudo dd if=/dev/disk2 of=/dev/disk3 bs=64k You also need enough local disk space for the image. This will take a long time, and there is no progress bar. Unmount of all volumes on disk2 was successful $ diskutil unmountDisk /dev/disk2 ⇐ unmount the source disk

$ diskutil list ⇐ list attached disks and partitions /dev/disk2 (external, physical):Ġ: FDisk_partition_scheme *120.0 GB disk2 Open Terminal, identify the disk and unmount it: If the following warning appears, click Ignore: You can use this procedure with any drive: eg, to clone an MGC Compact Flash from one with a known password. You can check progress while the command is running, by pressing Ctrl-T.Specifying a larger block size (bs=1m) doesn't seem to make much difference, though YMMV!.Using /dev/rdisk# (raw disk) in place of /dev/disk# is much faster.Be VERY careful with if (input file) and of (output file).If you can attach both disks, copy directly: sudo dd if=/dev/disk2 of=/dev/disk3 bs=64k.Make sure the destination has enough space, eg, is equal to (or greater than) the source size.

If the copy fails due to disk errors, try using the following command at step 3:ĭd if=/dev/disk2 of=/Users/mike/diskimage.img conv=noerror,syncĭd will take much longer using this option, errors are written as NUL bytes. The second dd command is almost the same, but if and of are reversed. Sudo dd of=/dev/disk2 if=/Users/mike/diskimage.img Attach and identify the destination disk ⇒Ħ. Sudo dd if=/dev/disk2 of=/Users/mike/diskimage.imgĤ. If the installation has primary and backup signalling servers, clone one at a time to avoid service interruption. Make a working copy of a Signalling Server hard disk This option can often recover a dead hard drive, or an unreadable file, but it does not repair the error. If the operation stops with an I/O error, try to salvage all readable data with conv=noerror,sync By adding sync, errors are padded with zero's (optional) bs=n sets both input and output block size (optional, default=512 byte blocks).

Mac disk image from drive