Dang it.
XenServer is 6.5.
XenCenter is 7.1 as of today.
The VM is headless Ubuntu 14.04 running Seafile.
I happen to also run a VM for XO but I don't know how that plays into this. Is XO better at extending partitions?
I eventually gave up trying to extend the partition anyway. The docs I found said I had to blast away the partition so I needed to move data around to do it. Just a pain in the butt. It was only a test install of Seafile anyway. I intend to build it up properly this round.
The only question is now, I really don't want to go through this again, or I need to set it up so changing drive size isn't as big a deal.
We've used up our 10GB of Box space so I could easily just throw, say, 50GB at the new setup and it would probably last us a half decade. But still, it would be nice to do this in a way where I can more easily adjust available space if the time comes.