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 1: Basics

Welcome everyone to this series on memory reclamation techniques in vSphere 7.x. This will be one more long series of posts after my previous series on uncovering virtual networking. In this series, we will try to understand the memory virtualization basics, memory reclamation techniques in vSphere (Specifically ESXi hosts), ESXi host Memory states, and sliding … Continue reading VMware vSphere 7.x Memory Reclamation-Part 1: Basics

VMware Memory reclamation techniques run cycle in vSphere 6.x Part-1

Why Memory reclamation: ESXi supports memory over commitment in order to provide higher memory utilization and higher ratio of consolidation. In order to effectively support memory over commitment, the hypervisor provides efficient host memory reclamation techniques. ESXi uses several techniques to reclaim virtual machine memory, which are: Sliding scale Method Transparent page sharing (TPS) Ballooning … Continue reading VMware Memory reclamation techniques run cycle in vSphere 6.x Part-1

VMware memory reclamation vSphere 6: Mem.minfreepct and sliding scale method PART2

Before I talk about sliding scale method, let's discuss about mem.memminfreepct value. Eventually this discussion will lead us to understanding sliding scale method.   What is mem.minfreepct value? MinFreePct determines the amount of memory that the VMkernel should keep free. This threshold is further subdivided in multiple memory thresholds i.e. High, Clear (New in vSphere … Continue reading VMware memory reclamation vSphere 6: Mem.minfreepct and sliding scale method PART2

VMware Memory Reclamation:Hypervisor Swapping PART6

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 is dependent of possibility to share memory pages, another reclamation technique of ballooning also depends on guest operating system response for memory allocation. Due … Continue reading VMware Memory Reclamation:Hypervisor Swapping PART6

VMware Memory Reclamation: Memory Compression Explained PART5

ESXi provides a memory compression cache to improve virtual machine performance when you use memory over commitment.  If the virtual machine’s memory usage reaches to the level at which host-level swapping will be required, ESXi uses memory compression to reduce the number of memory pages it will need to swap out. Because the decompression latency … Continue reading VMware Memory Reclamation: Memory Compression Explained PART5