I finally found some time to experiment with two new things with Windows Server 2016 (TP2), Storage Spaces Direct and Nano Server. Overall the experience of getting that up and running was straightforward and as advertised. The performance was as good as expected even though I’m testing on a virtualized setup with modest hardware. The resources consumed in order to deliver that service are pretty darn minimal. Between 300 and 550MB of RAM and 1.5GB and 2GB of storage for the OS drives. Looking at the list of running processes gives you a good sense of how minimal that setup is and how secure and manageable it will be. One thing that takes some getting used to, is how stripped the OS is. i.e. Right now, you have the cmdlet to change IP configuration but not DNS. I’m sure that will be added in builds following TP2.
Here are a few things I’ve noticed while diskspd against the Storage Spaces Direct cluster:
Another thing I noticed I didn’t expect was when a server that is part of the cluster is stopped/restarted, IO pauses for a few seconds. The first time I noticed this, I thought it was because I restarted the server which had some of the cluster resources, which causes a failover, which can take some time before everything comes back to normal. I then made sure every resources was running on the “first” cluster node and then went ahead and restarted/stopped the “last” node. Every time I did this, an IO pause occurred. I suspect it’s because the node serving the share has some backend connections for block redirection to that specific node and those need to be re-established/renegotiated with another node to serve those blocks. As those blocks are mirrored to other nodes in the cluster, I would have expected that process to be absolutely transparent.