vSphere 6.7 U2 & later CPU Scheduler modes: Default, SCA v1 and SCA v2

This post will be focussing specifically on working of CPU scheduler in Default, SCA v1 and SCA v2 modes in 6.7 U2 and later. VMware vSphere 6.7 U2 added new scheduler options (SCA v2) which provides security for L1TF vulnerability, while retaining as much performance as possible.  Note: SCA is the abbreviation for Side Channel … Continue reading vSphere 6.7 U2 & later CPU Scheduler modes: Default, SCA v1 and SCA v2

How to optimize Virtual machine vNIC transmit (Tx) performance?

In this post, we will discuss about using single or multiple vNICS on a VM and vmkernel networking CPU threads to optimize transmission rate of VM traffic. We can create a VM with single vNIC or multiple vNICs depending upon operational requirements. Using multiple vNICS on a VM could be for different types of traffic … Continue reading How to optimize Virtual machine vNIC transmit (Tx) performance?

VMware vSphere 7.x Memory Reclamation-Part 6: Hypervisor Swapping

This will be the last post in this series. In this post, we are going to discuss hypervisor swapping as next method after compression. ESXi employs hypervisor swapping to reclaim memory, if other memory reclamation techniques like ballooning, transparent page sharing, and memory compression are not sufficient to reclaim memory. Transparent Page Sharing (TPS) speed … Continue reading VMware vSphere 7.x Memory Reclamation-Part 6: Hypervisor Swapping

VMware vSphere 7.x Memory Reclamation-Part 5: Memory Compression Cache

In this post, we are going to discuss about memory compression cache technique used by ESXi host. In previous posts we have already discussed TPS and ballooning. So compression is the next technique in order that gets initialized when ESXi host is under memory contention. ESXi provides a memory compression cache to improve virtual machine … Continue reading VMware vSphere 7.x Memory Reclamation-Part 5: Memory Compression Cache

VMware vSphere 7.x Memory Reclamation-Part 4: Ballooning

After TPS in previous post, we will explore Ballooning reclamation technique in this post. Basically I am just following the order in which these techniques are initialized. Ballooning is a process where the hypervisor reclaims memory back from the virtual machine. Also if ballooning is started on an ESXi host, it indicates the beginning of … Continue reading VMware vSphere 7.x Memory Reclamation-Part 4: Ballooning

VMware vSphere 7.x Memory Reclamation-Part 3: Transparent Page Sharing (TPS)

Previously in Part-1:Basics and Part 2: MinFree, we discussed about memory reclamation, need for memory reclamation, ESXi memory states, sliding scale method for calculating MemMinFreePct value. In this post, we will explore sharing memory pages with memory reclamation technique called as Transparent Page Sharing or TPS. On an ESXi host, many workloads present opportunities for sharing … Continue reading VMware vSphere 7.x Memory Reclamation-Part 3: Transparent Page Sharing (TPS)

VMware vSphere 7.x Memory Reclamation-Part 2: Mem.MemMinFreePct

So here we are with another post in this series. In previous post we discussed basics of memory virtualization concepts and the need for memory reclamation. In this post we will explore ESXi host memory states, sliding scale method of calculating Mem.MemMinFreePct. As discussed in previous post, multiple VMs that run on ESXi host, share … Continue reading VMware vSphere 7.x Memory Reclamation-Part 2: Mem.MemMinFreePct