El cheapo 10Gbps networking
I’ve been hitting the limits of gigabit ethernet at home for quite a while now, and as I spend more time working with cloud technologies this started to frustrate me.
I’d heard of other folk getting good results with second hand Infiniband cards and decided to give it a go myself.
I bought two Voltaire dual-port Infiniband adapters – a 4X SDR PCI-E x4 card. And in a 2 metre 8470 cable, and we’re in business.
There are other, more comprehensive guides around to setting this up – e.g. http://davidhunt.ie/wp/?p=2291 or http://pkg-ofed.alioth.debian.org/howto/infiniband-howto-4.html
On ubuntu the hardware was autodetected; all I needed to do was:
modprobe ib_ipoib sudo apt-get install opensm # on one machine
And configure /etc/network/interfaces – e.g.:
iface ib1 inet static address 192.168.2.3 netmask 255.255.255.0 network 192.168.2.0 up echo connected >`find /sys -name mode | grep ib1` up echo 65520 >`find /sys -name mtu | grep ib1`
With no further tuning I was able to get 2Gbps doing linear file copies via Samba, which I suspect is rather pushing the limits of my circa 2007 home server – I’ll investigate futher to identify where the bottlenecks are, but the networking itself I suspect is ok – netperf got me 6.7Gbps in a trivial test.