☰

如何在访客上手动触发 virtio Balloon 驱动程序？

tag-icon • tag-icon memory virtual-machine qemu libvirt virtio
如何在访客上手动触发 virtio Balloon 驱动程序？

我希望在 QEMU 中运行的某个 Linux 来宾释放内存前主机面临内存压力。如何手动触发virtio 气球驱动程序以便它释放尽可能多的内存？

答案1

这样的事情似乎有效：首先减少来宾可用的内存量，然后（可选）将其恢复到原始设置。

virsh --connect qemu:///system qemu-monitor-command --domain NAME --hmp 'balloon 512'
# Wait for the balloon driver to release some memory
sleep 2
virsh --connect qemu:///system qemu-monitor-command --domain NAME --hmp 'balloon 4096'

或者，作为一个正确的脚本：

#!/bin/bash

set -eu

domain=$1
# How many MB to temporarily reduce the guest memory to; don't set this too
# low or the OOM killer will start killing.
reduced_memory=$2

hmp() {
    virsh --connect qemu:///system qemu-monitor-command --domain "$domain" --hmp "$1"
}

original_memory=$(hmp "info balloon" | grep = | cut -d '=' -f 2)
hmp "balloon $reduced_memory" > /dev/null
# Wait for the balloon driver to release some memory before setting it back
sleep 2
hmp "balloon $original_memory" > /dev/null

相关内容