I want to do a full backup of my router Linksys WRT1200AC V2 .
cat /proc/mtd show me 10 Partitions .Which partitions do I have to take?
And then root@OpenWrt:/# cat /dev/my mtd number > /tmp/image.bin
Sorry,for my bad English.Google-Translate works for me.
Or is better i am using the Image Builder ?
It is a NAND Device......
I would suggest either using the standard backup process (which will backup your config files and any other files/directories that you include in /etc/sysupgrade.conf (you will need to reinstall any user-installed packages) or using the image builder to make a custom image that includes all of your files and can also have all the user installed packages included, too. Cloning the raw storage is more complex, and it is more error-prone when attempting to re-write the data later.
In general, this is expected behavior. Creating a clone of the entire memory will obviously have the ability to restore things exactly to the state of that clone. This is useful to get back to a known state (especially if you mess something up of have some other type of issue like a hardware failure and then replace with an identical device). But it doesn't help if you are resetting to clear out packages that you don't want or to reset bad settings since you are literally restoring everything exactly as it was. It also will help with sysupgrade, and you likely won't be able to read the files normally to use as a reference if you are ever manually rebuilding your settings.
Custom images can be useful for a lot of people, as can the attended sysupgrade process. Here is an answer I wrote in a similar thread.