Hello, I had an RB110AHx2 with 5.18 firmware release, a 2Gb microSD for use dudeand nothing more.
I try to upload FW 5.19 but no space available. ??? 
I try to export my dude conf but “error not enought space”.
I had 1883.2Mb free on the SD and 13 Mb free on system.
How can I upgrade to the latests and future relese and backup dude configuration. (too much time lost for recover situation manually)
Thank you