Creating an Image File for a Whole Hard Drive

In the course of my work, I often have a 2.5" SSD that needs to burned into an image for safe-keeping or later restoration. In my case, it's a 120GB drive that can be plugged into a simple SATA-USB adapter cable (powered by the USB bus). So, the hardest part is the software side... and it's really not that hard.

All you really need is the Linux 'dd' command and a compression utility. I've added a few minor things to make it faster and more informative.

First, ensure your distro has pigz (a gzip utility that can actually use multiple CPU cores for faster compression) and pv (pipe viewer, so you can monitor progress).

Then, plug in your drive, grab its device name from dmesg (I usually get /dev/sdi, so will use that in examples here), and run fdisk to get its size. That's optional, but nice to have for progress.

# dmesg
<get device id/name from output>

# fdisk -l /dev/sdi
<get size in bytes from output below, usually first line>
Disk /dev/sdi: 120.0 GB, 120034123776 bytes

Finally, issue the command to create an image file and plug in the size you got above to the pv portion of the command (of course, make sure you have enough space on disk for the compressed image, first!)...

# dd if=/dev/sdi | pv -s 120034123776 | pigz --fast > /path/to/new/imgFile.dd.gz