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 […]
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 […]
I was made aware that eBPF was available now in RHEL via the below tweet from Brendan Gregg. As our main distro is RHEL I was intrigued to see what the release looked like and what was available. For those who don’t know the bcc-tools package contains the eBPF bcc toolset which allows new insights into […]
Hi as I have had a lot of traffic for the 3PAR performance I have added a short video below on how to import and use the overall Array Performance views.
Hi as I have had a lot of traffic for the 3PAR performance I have added two videos below on how to setup the host and array views which covers hosts and volumes. When looking at the performance data for the volumes you may notice that these are spiking in nature this is down to […]
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 […]
Just a quick plug really I am doing my presentation at the Scottish OUG on the 21st of this month. Agenda: http://www.oug.org/Scotland/Scotland2018/agenda.pdf Location: 21 June | Sheraton Grand Hotel, Edinburgh If you are coming along feel free to say Hi. Allan