Drobo not recognised on DVD DW boot


My Drobo has recently stopped mounting in Finder and Desktop however is visible in Disk Utility and Dashboard and looking healthy.

I have DiskWarrior and Drobo shows up when running from the utility but I get the error - boot from CD/DVD not enough memory.

HOWEVER, when I boot from the DVD DW doesn’t recognise the Drobo at all!!

Drobo Gen2 USB, 2010 iMac 27inch, 2012 Macbook Air i7, 8GB

hi, im not too sure about macs, but are there any other programs running on your mac that you might be able to close, in order to free up some memory to be able to run that disk utility you were trying while the mac is running?