Create a disk image of my MacBook

I understand that timemachine is keeping a snapshot of my Mac at all points of time on my thunderbolt external harddisk.

What I want is a disk image of my present system, so that in future if everything crashes (because I also have bootcamp running and I am always scares something will mess up as it has in the past) I should be able to simply restore this image on my drive and have my system in exactly the form as I have it today.

Without using the paid softwares out there is it possible to accomplish this using Disk Utility or terminal.

At this point when I try to create an image of my Mac drive in Disk Utility it is greyed out, even if I open disk utility from recovery mode it is greyed out.

Even if I use sudo dd or sudo hdiutil, or even if I run /usr/bin/hdiutl from recovery mode, it always saves the Volume is busy and so the image cannot be created.

Please let me know if it is possible to create a disk image of the entire Mac partition and restore it at a later point in time to get back the system in the state it was in at the time of the creation of the image.

Thanks in advance.