Backing up system to USB drive

Question

I intend to back up my Ubuntu system to a USB stick before attempting to dual boot it with Windows 7. There are a few things I want to know:

1. What file system should I use? Presently, the USB stick uses FAT32, but the backup file would be larger than the 4GB that this allows. I am hoping to maintain compatibility with Windows. Some people suggest exFAT, but this apparently has poor support with Ubuntu and disk utilities.
2. What backup utility and kind of backup should I use?
3. I will probably back up a full system image and, separately, all the directories that contain whatever I would have modified during use of Ubuntu (such as documents and installed packages). What directories should I back up in order to achieve this?
4. Is it possible to restore a backup image of Ubuntu after installing Windows 7 and maintain all my data and packages?
5. I also plan to later update Windows 7 to Windows 10. Should this influence any of my choices?

Answer 1

When you ask multiple questions, you need to find one expert versed in multiple areas which becomes more unlikely the more questions you put into... well, one question! ;-) However, someone asked me to help you out, so I'll go for it:

1. Use NTFS: none of the fuss, all of the advantages (for a certain definition of fuss )
2. Just use CloneZilla, but read its manual before you start! (Hint: use the disk to image option and take default options)
3. Good! Back up your / partition without the /home as you already have a déjà-dup backup of that (you do have a data back-up, don't you???)
4. Yes, but it will erase the Win7 install.
5. Meh... The Win10 upgrade might erase your boot record again (which the Win7 install will do also: one response: Boot Repair )

Happy backing up! ;-)