Problems with qemu-guest-agent in VPS

Support
1

I can’t start qemu-guest-agent in my VPS

I execute the command via SSH:

systemctl status qemu-guest-agent

I receive the message:

 qemu-guest-agent.service - QEMU Guest Agent
    Loaded: loaded (/usr/lib/systemd/system/qemu-guest-agent.service; enabled; v>
    Active: inactive (dead)

I execute the command via SSH for activating:
sudo systemctl enable qemu-guest-agent

I receive the message:

Unit /usr/lib/systemd/system/qemu-guest-agent.service is added as a dependency to a non-existent unit dev-virtio\x2dports-org.qemu.guest_agent.0.device.

I execute the command via SSH:
sudo chkconfig qemu-guest-agent on

I receive the message:

Note: Forwarding request to 'systemctl enable qemu-guest-agent.service'.
Unit /usr/lib/systemd/system/qemu-guest-agent.service is added as a dependency to a non-existent unit dev-virtio\x2dports-org.qemu.guest_agent.0.device.

I execute the command via SSH:
sudo systemctl restart qemu-guest-agent

Show the message:
A dependency job for qemu-guest-agent.service failed. See 'journalctl -xe' for details.

The command journalctl -xe | grep qemu show:

Apr 02 23:28:46 admin.lacaverna.net sudo[441657]:   centos : TTY=pts/0 ; PWD=/home/centos ; USER=root ; COMMAND=/bin/systemctl enable qemu-guest-agent
Apr 02 23:30:48 admin.lacaverna.net sudo[441894]:   centos : TTY=pts/0 ; PWD=/home/centos ; USER=root ; COMMAND=/bin/systemctl start qemu-guest-agent
Apr 02 23:32:18 admin.lacaverna.net systemd[1]: dev-virtio\x2dports-org.qemu.guest_agent.0.device: Job dev-virtio\x2dports-org.qemu.guest_agent.0.device/start timed out.
Apr 02 23:32:18 admin.lacaverna.net systemd[1]: Timed out waiting for device dev-virtio\x2dports-org.qemu.guest_agent.0.device.
-- Subject: Unit dev-virtio\x2dports-org.qemu.guest_agent.0.device has failed
-- Unit dev-virtio\x2dports-org.qemu.guest_agent.0.device has failed.
-- Subject: Unit qemu-guest-agent.service has failed
-- Unit qemu-guest-agent.service has failed.
Apr 02 23:32:18 admin.lacaverna.net systemd[1]: qemu-guest-agent.service: Job qemu-guest-agent.service/start failed with result 'dependency'.
Apr 02 23:32:18 admin.lacaverna.net systemd[1]: dev-virtio\x2dports-org.qemu.guest_agent.0.device: Job dev-virtio\x2dports-org.qemu.guest_agent.0.device/start failed with result 'timeout'.
Apr 02 23:32:27 admin.lacaverna.net sudo[441948]:   centos : TTY=pts/0 ; PWD=/home/centos ; USER=root ; COMMAND=/sbin/chkconfig qemu-guest-agent on
Apr 02 23:35:39 admin.lacaverna.net sudo[442262]:   centos : TTY=pts/0 ; PWD=/home/centos ; USER=root ; COMMAND=/sbin/service qemu-guest-agent start
Apr 02 23:37:09 admin.lacaverna.net systemd[1]: dev-virtio\x2dports-org.qemu.guest_agent.0.device: Job dev-virtio\x2dports-org.qemu.guest_agent.0.device/start timed out.
Apr 02 23:37:09 admin.lacaverna.net systemd[1]: Timed out waiting for device dev-virtio\x2dports-org.qemu.guest_agent.0.device.
-- Subject: Unit dev-virtio\x2dports-org.qemu.guest_agent.0.device has failed
-- Unit dev-virtio\x2dports-org.qemu.guest_agent.0.device has failed.
-- Subject: Unit qemu-guest-agent.service has failed
-- Unit qemu-guest-agent.service has failed.
Apr 02 23:37:09 admin.lacaverna.net systemd[1]: qemu-guest-agent.service: Job qemu-guest-agent.service/start failed with result 'dependency'.
Apr 02 23:37:09 admin.lacaverna.net systemd[1]: dev-virtio\x2dports-org.qemu.guest_agent.0.device: Job dev-virtio\x2dports-org.qemu.guest_agent.0.device/start failed with result 'timeout'.
Apr 02 23:38:10 admin.lacaverna.net polkitd[1138]: Operator of unix-process:442338:52292525 FAILED to authenticate to gain authorization for action org.freedesktop.systemd1.manage-units for system-bus-name::1.46185 [systemctl start qemu-guest-agent] (owned by unix-user:centos)
Apr 02 23:38:16 admin.lacaverna.net sudo[442393]:   centos : TTY=pts/0 ; PWD=/home/centos ; USER=root ; COMMAND=/bin/systemctl start qemu-guest-agent
Apr 02 23:39:14 admin.lacaverna.net sudo[442438]:   centos : TTY=pts/0 ; PWD=/home/centos ; USER=root ; COMMAND=/bin/systemctl enable --now qemu-guest-agent
Apr 02 23:39:46 admin.lacaverna.net systemd[1]: dev-virtio\x2dports-org.qemu.guest_agent.0.device: Job dev-virtio\x2dports-org.qemu.guest_agent.0.device/start timed out.
Apr 02 23:39:46 admin.lacaverna.net systemd[1]: Timed out waiting for device dev-virtio\x2dports-org.qemu.guest_agent.0.device.
-- Subject: Unit dev-virtio\x2dports-org.qemu.guest_agent.0.device has failed
-- Unit dev-virtio\x2dports-org.qemu.guest_agent.0.device has failed.
-- Subject: Unit qemu-guest-agent.service has failed
-- Unit qemu-guest-agent.service has failed.
Apr 02 23:39:46 admin.lacaverna.net systemd[1]: qemu-guest-agent.service: Job qemu-guest-agent.service/start failed with result 'dependency'.
Apr 02 23:39:46 admin.lacaverna.net systemd[1]: dev-virtio\x2dports-org.qemu.guest_agent.0.device: Job dev-virtio\x2dports-org.qemu.guest_agent.0.device/start failed with result 'timeout'.
Apr 02 23:42:26 admin.lacaverna.net sudo[442691]:   centos : TTY=pts/0 ; PWD=/home/centos ; USER=root ; COMMAND=/bin/sed -i /BLACKLIST_RPC=/cBLACKLIST_RPC= /etc/sysconfig/qemu-ga
Apr 02 23:42:40 admin.lacaverna.net sudo[442694]:   centos : TTY=pts/0 ; PWD=/home/centos ; USER=root ; COMMAND=/bin/systemctl restart qemu-guest-agent
Apr 02 23:42:40 admin.lacaverna.net systemd[1]: Unnecessary job for dev-virtio\x2dports-org.qemu.guest_agent.0.device was removed.
-- Subject: Unit dev-virtio\x2dports-org.qemu.guest_agent.0.device has failed
-- Unit dev-virtio\x2dports-org.qemu.guest_agent.0.device has failed.
Apr 02 23:42:40 admin.lacaverna.net systemd[1]: qemu-guest-agent.service: Bound to unit dev-virtio\x2dports-org.qemu.guest_agent.0.device, but unit isn't active.
-- Subject: Unit qemu-guest-agent.service has failed
-- Unit qemu-guest-agent.service has failed.
Apr 02 23:42:40 admin.lacaverna.net systemd[1]: qemu-guest-agent.service: Job qemu-guest-agent.service/start failed with result 'dependency'.

Can you help me? When my vps execute backup, the vps hangs

2

Hi, mcastilloperez,

Thanks for providing these detailed errors!
A couple additional questions for you:

What version of Alma Linux is this running on the VPS? 8.9, 9.3, etc. ?
Please provide the output of these commands:

cat /etc/redhat-release

and

uname -a

Are you sure the VPS is using qemu, and not kvm?
Please provide the output of this command:

systemd-detect-virt

Lastly, as this often can complicate matters (at least as I have seen on many posts), does your VPS use or require cPanel ?

Thanks,

lg

4

Did you start QEMU correctly? I believe you have not enabled serial port from the host itself

5

cat /etc/redhat-release

show:

AlmaLinux release 8.9 (Midnight Oncilla)

uname -a

show
Linux admin.lacaverna.net 4.18.0-513.18.1.el8_9.x86_64 #1 SMP Thu Feb 22 03:02:37 EST 2024 x86_64 x86_64 x86_64 GNU/Linux

systemd-detect-virt

show
kvm

I use cpanel

cheers!

6

How can I enable the serial port?

7

If you are using libvirt xml config, here is the part you need to add:

<channel type='unix'>
  <target type='virtio' name='org.qemu.guest_agent.0'/>
  <address type='virtio-serial' controller='0' bus='0' port='1'/>
</channel>
8

I didn’t find this file

9

Libvirt files are stored in: /etc/libvirt/qemu

10

don’t exist, I use the vps (vm) I don’t have access to the host, cheers!

11

Ask your host to enable that for you. Also, why do you wanna go for guest-agent?

12

My problem really is that my server hangs when the backup is made with the OVH service, and in fact they recommend having QEMU active, and I read that having it active would help prevent what I’m telling you from happening.

13

I can see quite opposite in this article describing the exact issue though in cPanel environment.

14

I even removed the qemu and it still happens, in fact the command systemctl status qemu-guest-agent returns inactive (dead), you can read it above