To backup an entire hardisk
#dd if=/dev/sda of=/dev/sdb
sda is the source hardisk and sdb is the external hardisk to which am taking backup
“if” represents input file and “of” respresents output file….
if we give parameter “conv=noerror” then it will continue to copy if there are read errors…else command may fail due to read error
#dd if=/dev/sda of=/dev/sdb conv=noerror
To make image of a hardisk
#dd if=/dev/sda of=~/Desktop/hd_img.iso
Consider am having a bootable usb with a custom OS with some settings saved in it…To make an image of that
Make image of the bootable usb
#dd if=/dev/sdb of=~/Desktop/puppy.img
The above command will make an image of the bootable usb
Now connect the blank usb and make it bootable
dd if=~/Desktop/puppy.img of=/dev/sdb oflag=direct
Always run dd command as root user…use df command to know the drives else you may loose the data…
the same command with a view on the progress of the dd command:
# apt-get install pv
# pv -tpreb /dev/sda | dd of=/storage/disk.img