I understand that this is a question that is asked quite often, but unfortunately most answers involve using a LiveCD which in this case isn't possible. I'm currently using a dedicated server running Ubuntu 14.04 LTS on a host that allocates most of the disk space to the /home directory. Unfortunately, I have run out of disk space on the root directory, effectively breaking my server. My conundrum is that I already have quite a bit of data set up on the server, making it difficult to back everything up locally and reinstall the dedicated server using a better allocation.
Essentially what I'm looking for is a way to allocate everything currently on the .home directory to the / directory. From what I've read, there's no way to reallocate disks while in operation, so I really don't know where to go from here. My host does offer a "Rescue Mode" which appears to create a temporary virtual machine that mounts the current file tree in a /mnt directory, but I'm not too sure if I can repartition the disk through that. It also has an option to "Netboot", which I haven't tried yet but is always a possibility.
I am not too sure where to go from here, so any help you can provide would be much appreciated!