I've just done that and possibly failed even with this simple task! After I connected the device and the LAN cable, I powered it up. Ten second later I noticed the LAN cable was not holding inside and I pulled the cable to check if the clip is not broken. Turns out I did not inserted it hard enough, it has some rubber cover that prevented it to go in all the way. Now I am not sure if it reached the point where it needed the LAN connection.
I opened the router page and I can see the IP assigned to Raspberry Pi. I can ping the IP (it does not respond to "ping raspberrypi"), but I can't open OMV web page. I hope the installation is in progress and a bit later it will be accessible. I am on fast internet (about 40 Mbps) so the update should take reasonably little time.
I tried to connect via SSH using Putty (I tried admin/openmediavault and root/openmediavault because I can't remember which one to use) and I get "access denied". There are about 45 minutes since I turned it on first time. Perhaps it got angry on me for removing the LAN Cable.
Any chance to power it back or should I reflash the SD Card and start over?
I left the external hard drive off. I think I read earlier somewhere to connect it after the installation is complete.
I noticed the MAC address of my Raspberry Pi has changed between the different OS installations. I thought it is stored in hardware...