ps. I do have 4 partitions for the images. My system is built to the internal 500Gb hdd I fitted.
Really my reason for asking about this is because the machine refuses to boot (normal boot - not talking about emergency flashing here) with a USB stick inserted into one of the 3 USB ports and it's got me thinking that Start_1 must have an image (but I am probably totally wrong). I am thinking that if Start_1 is empty then the box will, if it has a usb inserted, try to boot from that and not look at the Start_2 from where it is being asked to reboot from in the first place!?!? If I insert a flash drive after booting up to start_2 I can use it fine (to play movies but If I leave it in and restart or deep_standby/start then the box gets to the wording "boot" on the front panel and no further - it hangs at this point like to can't see start_2 or is not even looking for it - its like its looking for an image on the flash drive but its not there and then just hanging. the usb stick itself is fine. I have used it for reflashing using the front panel button technique and all was well).
The reason I got rid of the openvix in start_1 was because when I was in openvix I tried to swap over to start_2 (which had OpenATV) using the menus and it did not boot and I could do nothing (it bricked it). I then had to recover the system using a USB stick and special power button at front of box to reflash OpenATV (as I preferred openATV over OpenVIX).
As soon as OpenATV was up and running I immediately deleted the Openvix in start_1 so I would never make that mistake again :-) Not sure why it did that but it is my first enigma2 box and I had it for all of 2 days and was "testing" and familiarizing myself with the system so I probably did something stupid.
What I plan to do (at some point) is to do as you suggest. Backup_full my OpenATV that is stable and I'm happy with, Flash this to to start_1. I then plan to rename the OpenATV in Start_2 to OpenATV_Testing.
day-to-day boot to Start_1 (now my current image). When I want to play/test new plugins and such I plan to boot to Start_2 - make my tests in there and if all bad then I can delete it and start again but always having my Main (solid) image in Start_1.
Hope that makes sense.
Cheers,
Paul