It is very important to make a backup of your SD card of the pi-top from time to time. This allows to easily recover if you have a problem with the software.
Personally, I prefer to clone my SD card directly on the pi-top. For this I am using a cheap USB SD card reader, which I attach to one of the USB ports of the Raspberry Pi. The one I am using is one I got with an SD card from Eye-Fi, but any one should work. Because the SD card reader does not fit in the opening of the pi-top, I am connecting it with a short usb extender. The one I am using came with a mouse, but again any one or any usb extender cable should work.
See the attached picture
With such a setup, you can now use
menu->Accessories->SD Card Copier
to clone your internal SD card to the one in the card reader
The advantage of this procedure is that you end up directly with a second bootable SD card.
Thanks Rene, I stumbled across this a week ago and backed up both of my Pi's. I was impressed with the speed,
Thanks for all your support on these forums!
also you can use win32diskimager to image the sd card. I do this so that I have a backup of my pi-top sdcard (32gb) on my pc's internal hard disk. i use a faster SD card (samsung evo plus) so creating and restoring the image doesn't really take all that long.
Have done that also, guess I am paranoid!