DD file is a disk image file and replica of a hard disk drive. The file having extension .dd is usually created with an imaging tool called DD. The utility provides command line interface to create disk images in a system running UNIX & LINUX OS.
DD file, sometimes referred as forensic dd image, is often used to investigate Linux hard disk data in Windows OS.
In Linux, DD utility uses the following command to create a dd image file:
dd if=/dev/hdr of=mydisk.dd if is an input file /dev/hdr is a physical disk of linux of is an output file mydisk.dd is a name of the destination file
dd if=/dev/hdr of=mydisk.dd bs=64836 conv=noerror,sync bs is block size conv=noerror parameter makes the command continue to run even if any read error occurs from source drive. sync If error occurs then null fill the rest of the block
In Windows, DD utility uses the following command to create a dd disk image:
dd.exe if=\\.\PhysicalDrive0 of=d:\images\PhysicalDrive0.dd
This cmd will create a duplicate copy of a source drive