Conrad's blog

Dynamic Memory Management - Proxmox VE

Thu, 06 Oct 2022 22:25:01 +0800

Dynamic Memory Management 动态内存管理

Introduction

Optimized and effective memory management is a key factor in virtualization environments. KSM and Auto-Ballooning enables sophisticated and economic configurations for physical RAM utilization.

优化和有效的内存管理是虚拟环境的关键因素，KSM和Auto-Ballooning为物理内存管理提供了复杂且实用的配置。

KSM

KSM (Kernel Samepage Merging) is running in the Linux kernel and scans the memory of all the virtual machines running on a single host, looking for duplication and consolidating. With KSM we’re able to improve virtual machine density by as much as 300% without impacting performance. One of the great benefits of using Linux as the hypervisor means KSM is not limited to KVM and virtual machines, but can also reduce memory pressure with normal Linux applications.

Create a Swap File on Linux

Thu, 11 Aug 2022 01:21:50 +0800

A swap file lets the kernel move idle pages out of RAM onto disk. It’s handy on small-memory hosts (VPS, VMs) that have no dedicated swap partition, and unlike a partition it can be resized or removed without repartitioning.

Create the swap file

# Allocate a 1 GiB file. dd is preferred over fallocate here because
# swapon rejects files with holes on some filesystems (e.g. ext4, XFS).
dd if=/dev/zero of=/swapfile bs=1M count=1024 status=progress

chmod 0600 /swapfile   # only root may read/write the swap file
mkswap /swapfile       # format it as swap space
swapon /swapfile       # enable it immediately

Make it persistent

Add an entry to /etc/fstab so the swap file is mounted on every boot. The grep guard keeps this idempotent — running it twice won’t add a duplicate line.

My First Post

Fri, 05 Aug 2022 16:24:31 +0800

Hello world…

About Me

Fri, 05 Aug 2022 01:03:03 +0800

This is my first static blog.

Just try it.