This is for anyone trying to transfer from another NAS to the WD: I finally figured out how to SSH in–there was this insanely goofy arbitrary user name applied to ssh that only showed up in small print when pressing the on button for SSH in the browser interface prior to setting up the password–I never could figure out how to mount the external NAS from the command line on the WD EX2.
What I eventually did was connect the QNAP, WD EX2, and a mac mini that I had hanging around (dedicating my laptop to hours of copying was not something that I could do) to a gigabit switch, set 9000 MTU jumbo frames on the QNAP, WD, and mac mini, and then mounted the QNAP and WD on the mac, an then ran a few rsync commands. It took a little over a day to move 2 TB.
I know that this is the supported way, and it would have likely taken about the same amount of time to do it directly as an rsync from the QNAP to the WD, but it just seemed really cumbersome. People out there must be, as I did, wanting to replace one NAS with another, and dragging and dropping on a filesystem over WiFi would take intractably long as NAS systems become commonly larger than 1 TB. So if ssh’ng into the WD EX2 is a clearly discouraged but still supported feature, and I’m guessing that’s the case because WD understandably doesn’t want to allocate support staff to systems internally reconfigured by users, why not build a one button old NAS to your new WD transfer?
Just a thought.