Blog – Steve Scargall

Using Linux Kernel Memory Tiering

In this post, I’ll discuss what memory tiering is, why we need it, and how to use the memory tiering feature available in the mainline v5.15 Kernel. What is Memory Tiering? With the advent of various new memory types, some...

June 10, 2022

How To

How To map VMWare vSphere/ESXi PMem devices from the Host to Guest VM

In this post, we’ll use VMWare ESXi 7.0u3 to create a Guest VM running Ubuntu 21.10 with two Virtual Persistent Memory (vPMem) devices, then show how we can map the vPMem device in the host (ESXi) to “nmem” devices in...

February 22, 2022

CXL How To Linux

How To Emulate CXL Devices using KVM and QEMU

What is CXL? Compute Express Link (CXL) is an open standard for high-speed central processing unit-to-device and CPU-to-memory connections, designed for high-performance data center computers. CXL is built on the PCI Express physical and electrical interface with protocols in three...

January 20, 2022

How To Build a custom Linux Kernel to test Data Access Monitor (DAMON)

How To Linux

How To Build a custom Linux Kernel to test Data Access Monitor (DAMON)

DAMON is a data access monitoring framework subsystem for the Linux kernel. DAMON (Data Access MONitor) tool monitors memory access patterns specific to user-space processes introduced in Linux kernel 5.15 LTS, such as operation schemes, physical memory monitoring, and proactive...

December 23, 2021

Resolving commands ‘Killed’ on GCP f1-micro Compute Engine instances

Linux

Resolving commands ‘Killed’ on GCP f1-micro Compute Engine instances

When I want to perform a quick task, I generally spin up a Google GCP Compute Engine instance as they’re cheap. However, they have limited resources, particularly memory. When refreshing the package repositories, it’s quite easy to encounter an Out-of-Memory...

December 20, 2021

How To Monitor Persistent Memory Performance on Linux using PCM, Prometheus, and Grafana

How To Linux Performance

How To Monitor Persistent Memory Performance on Linux using PCM, Prometheus, and Grafana

In a previous article, I showed How To Install Prometheus and Grafana on Fedora Server. This article demonstrates how to use the open-source Process Counter Monitor (PCM) utility to collect DRAM and Intel® Optane™ Persistent Memory statistics, and visualize the...

September 16, 2021

Using ltrace to see what ipmctl and ndctl are doing

How To Linux Performance Troubleshooting

Using ltrace to see what ipmctl and ndctl are doing

Occasionally, it is necessary to debug commands that are slow. Or you may simply be interested in learning how the tools work. While there are many strategies, here are some simple methods that show code flow and timing information. To...

June 23, 2021

How To

How To Install and Boot Microsoft Hyper-V 2019 from Persistent Memory (or not)

In a previous post I described how to install and boot Fedora Linux using only Persistent Memory, no SSDs are required. For this follow on post, I attempted to install Microsoft Windows Server 2022 onto the persistent memory. TL;DR – I was...

June 17, 2021