Adding Numa information to mpstat

I use mpstat a lot and at times want to know if a numa node is busy or at times a specific core. Previously I would post process the mpstat data after comparing the data to the output of lscpu. A while ago I wrote a perl script to map this out and reworked this […]

Mapping VSAN components

Recently I had been asked to look at some performance issues on a bunch of VMs which were showing increased write latency. But how do you know where the VM is sending it’s I/O in such a distributed system? With VSAN the compute resource for a VM could be on one server where all I/O […]

CPU Spikes when calling a SCSI INQUIRY

We were seeing some spike in CPU usage every 15 minutes on some new servers. As these systems were idle i.e. no workload apart from the operating system this makes an investigation slightly easier as we don’t have any application workloads to add to the mix. Below we can see an example of the spikes […]