# Cloudstack kvm vm boot error

**URL:** <https://forums.linbit.com/t/cloudstack-kvm-vm-boot-error/721>\
**Category:** General\
**Tags:** cloudstack\
**Created:** [April 3, 2025, 2:56am UTC](https://forums.linbit.com/t/cloudstack-kvm-vm-boot-error/721 "2025-04-03T02:56:16Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![cassiomc1](https://avatars.discourse-cdn.com/v4/letter/c/51bf81/32.png) [@cassiomc1](https://forums.linbit.com/u/cassiomc1)\
**Post date:** [April 3, 2025, 2:56am UTC](https://forums.linbit.com/t/cloudstack-kvm-vm-boot-error/721/1 "2025-04-03T02:56:16Z")

</div>

Hello, I’m having boot errors on the VMs, when booting Linux it gives a fatal error, I read that changing guest.cpu.mode to host-model fixed the problem but I don’t know where to change it, when I change agent.properties the file is overwritten by the cloudstack agent service, does anyone know how to change this parameter permanently?

---

<div class="post-metadata">

**Author:** ![nischalnischal](https://avatars.discourse-cdn.com/v4/letter/n/dbc845/32.png) [@nischalnischal](https://forums.linbit.com/u/nischalnischal)\
**Post date:** [April 3, 2025, 3:46am UTC](https://forums.linbit.com/t/cloudstack-kvm-vm-boot-error/721/2 "2025-04-03T03:46:51Z")

</div>

Hi

Please change the settings guest.cpu.mode=host-model in the

/etc/cloudstack/agent/agent.properties file in the KVM host and after this you can restart the agent using

systemctl restart cloudstack-agent

Please perform this on all the KVM hosts.

Please refer the link

> **[Host KVM Installation — Apache CloudStack 4.20.0.0 documentation](https://docs.cloudstack.apache.org/en/latest/installguide/hypervisor/kvm.html#configure-cpu-model-for-kvm-guest-optional)**

Please let us know if you need any other help

---

<div class="post-metadata">

**Author:** ![cassiomc1](https://avatars.discourse-cdn.com/v4/letter/c/51bf81/32.png) [@cassiomc1](https://forums.linbit.com/u/cassiomc1)\
**Post date:** [April 3, 2025, 12:37pm UTC](https://forums.linbit.com/t/cloudstack-kvm-vm-boot-error/721/3 "2025-04-03T12:37:02Z")

</div>

Hi  
the problem is that everything I change in /etc/cloudstack/agent.properties is removed after the cloudstack agent service is restarted, I don’t know how to persist these changes.

---

<div class="post-metadata">

**Author:** ![nischalnischal](https://avatars.discourse-cdn.com/v4/letter/n/dbc845/32.png) [@nischalnischal](https://forums.linbit.com/u/nischalnischal)\
**Post date:** [April 3, 2025, 1:22pm UTC](https://forums.linbit.com/t/cloudstack-kvm-vm-boot-error/721/4 "2025-04-03T13:22:22Z")

</div>

hi @cassiomc1

Thats a weird problem Could you please check with the cloudstack community about this, if this an old bug which is occuring, which version of Cloudstack are you using ?