I'm trying out a home cloud set up using a Raspberry Pi 2 Model B, and I've found the upload / download speed slower than expected.

I came across this article:

http://www.jeffgeerling.com/blogs/jeff-geerling/getting-gigabit-networking

describing how the author plugged in a USB3 Gigabit Ethernet adapter, and managed to up his throughput from 94 to 222 Mbps. 

I thought I'd give it a go. 

Two issues arose: 

1. Would the adapter I bought from Amazon for £10 work with the Pi?

2. What exactly should I do to /etc/network/interfaces to get the adapter to work, if it would?

The original author just said "and adding a line for the new eth1 adapter..." - a number of people asked in the comments what that meant, but they were ignored.

So here are my answers:

1. I got a "USB Network Adapter, Rankie® SuperSpeed USB 3.0 to RJ45 Gigabit Ethernet Network Adapter" - and yes, it works. There are no LED lights on it, which I think I would have preferred, but it works.

2. Simples. I got this right by trial and error (ie, I tried something, and it worked)

First, plug in the adapter to the Pi.

Then edit the /etc/network/interfaces file:

sudo nano /etc/network/interfaces

Then copy the eth0 line, but for eth1, ie add:

iface eth1 inet manual

And save the file. (Ctrl-O, Ctrl-X)

And reboot your Pi.

sudo reboot

If you swap the ethernet cable onto your new adapter, you can now access the Pi via that.

NB It might have a new IP address, and certainly will have a new MAC address.

For various reasons I've got my router pre-assigning a particular address to the Pi, so I had to re-do that for the new MAC address.