I installed OMV 4 on my Odroid C2 using OMV_4_Odroid_C2.img.xz dated 2018-06-03. MD5 checked out.
I ran the package updates in the webui and all seemed fine but since a reboot, no USB drives are detected.
I click 'scan' under the drives section of the webui - only the system's SD card is listed.
I've tried a few known good drives (external HDD and flash drives) - the indicator lights on the drive don't even light up on connection to USB port.
I tried booting from my old OMV 3 SD card, to make sure it's not a hardware problem - drives worked fine.
I tried starting again, reflashing the image - again it's fine before I install updates, but same problem after updates.
Any suggestions welcome!