Increasing the bramble

I decided to increase the size of the cluster - just at the wrong time.

I have a number of older Pi's (4 x Pi2B and 6 x Pi3B's) sitting around gathering dust. I have enough power adapters and I managed to find enough network cables to get them going. I even found a spare 6 socket power board. After a bit of furniture rearranging I had somewhere to put them. I flash a bunch of SD cards for them and bring them up one by one. Everything is going well so far.

Then I find that a number of the existing compute nodes only have a couple of tasks instead of the usual 4 each. The new ones aren't getting work either. After a bit of looking at logs it seems Einstein's scheduler is telling me it hasn't got any work. A quick check of the Einstein server status page tells me otherwise. I have a look at their scheduler log and it doesn't offer any clue other than it doesn't think there is any work available.

That brings Marks Rpi Cluster up to 12 Pi3B+ nodes and 10 Pi3B as compute nodes. I didn't use the Pi2B's as I think they are too slow and besides I don't have enough power adapters or network cables.

While I was at it I also updated the nfs server (a Pi3B+ with a PiDrive) to Raspbian Buster. I had to find my original blog post on how to setup an nfs server. It was the last Pi that I needed to update so now the whole cluster is running buster.