[ubuntu] Linux swap partition not on VDI image.

I converted my Linux OS (Ubuntu 15.10) on SSD to a virtualbox vdi. Only when I started to boot from it (and it seemed to boot just fine) did I remember that the swap partition for my OS was on a separate physical disk! It doesn't finish booting and it drops to a root shell under the image, but it says read-only when I try to edit something say in nano. What to do?

Your answer/help should go under number 2.

1. Do I need to rectify the situation on the physical disk then reimage?
2. Is there a way to avoid scenario #1?

Thanks a mil!