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 […]

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 […]

Building a dynamic QOS with eBPF and Cgroups

In my previous posts I have shown how the SolidFire Array QOS  implements QOS on a per volume basis. As I was looking for a new project I asked myself could I write a similar QOS program which runs on a virtual machine? I wondered could I dynamically change the Linux built-in QOS(throttling) which is […]