How to backup and restore MBP hard drive before reinstalling OS X? My MBP Retina 13″ late 2012 is showing the stop sign and I know that I need to reinstall my OS. I have not got my hard drive backed up with Time Machine. Is there a way in which I can backup my hard drive to an external drive using Disk Utility and then restore it back once I have reinstalled the OS (I have to restore as for some reason I don't have enough space or something)?
Absolutely - this is a good plan in general - having a bootable backup in addition to a Time Machine interval backup.

I like to get a SD card / micro SD card and install an emergency boot OS with just enough tools to fix any situation.


How do I make a bootable USB flash drive a Mac?


I would do that before making any changes. Next, you will want to measure how large your drive is - open Apple Menu - about this Mac and look in storage:



For this Mac, you would need 185 GB of space.


Connect a USB drive and partition it to have one free partition that's at least 5 GB larger than the space needed. (I would go 15GB or more larger if you care about speed or ever booting from that partition)
Erase the partition you will be using and format it as OS X Extended and name it "target" or something unmistakable.
Shut down the Mac and hold R when booting to boot to Recovery HD
Use Disk Utility from Recovery to restore data from Macintosh HD to target
Wait - enjoy some tea or coffee or whatever
When things are done, power off and boot holding option - you should see two boot drives with different icons on the grey screen and can test booting from the clone.