Install Guest Agent inside Proxmox virtual machine.

List virtual machines.
proxmox$ qm list
VMID NAME STATUS MEM(MB) BOOTDISK(GB) PID 100 ubuntu-jammy-jellyfish stopped 2048 20.00 0 102 debian-bullseye stopped 2048 20.00 0 3001 consul-1 running 2048 20.00 397130 3002 consul-2 running 2048 20.00 396537 3003 consul-3 running 2048 20.00 396585
Get VM configuration.
proxmox$ qm config 3003
boot: order=scsi0;ide2;net0 cores: 2 ide2: local:iso/ubuntu-22.04-live-server-amd64.iso,media=cdrom,size=1432338K memory: 2048 meta: creation-qemu=6.2.0,ctime=1656270900 name: consul-3 net0: virtio=2E:AE:A1:14:0E:BF,bridge=vmbr0,firewall=1 numa: 0 ostype: l26 scsi0: local-lvm:vm-3003-disk-0,cache=writethrough,iothread=1,replicate=0,size=20G,ssd=1 scsihw: virtio-scsi-single smbios1: uuid=8580553f-388e-42b1-9510-eca6e809be34 sockets: 1 vga: std vmgenid: 79703a1a-fb97-4f86-ac69-b5e1f7372c1b
Enable agent.
proxmox$ qm set 3003 --agent 1
update VM 3003: -agent 1
Inspect pending changes.
proxmox$ VMID=3003 && diff <(qm config $VMID --current) <(qm config $VMID)
0a1 > agent: 1
Reboot virtual machine.
proxmox$ qm reboot 3003
Execute any Qemu Guest Agent command to test communication.
proxmox$ qm agent 3003 ping
QEMU guest agent is not running
Install QEMU guest agent inside virtual machine.
milosz@jammy:~$ sudo apt install qemu-guest-agent
Reading package lists... Done Building dependency tree... Done Reading state information... Done The following NEW packages will be installed: qemu-guest-agent 0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded. Need to get 0 B/253 kB of archives. After this operation, 859 kB of additional disk space will be used. Selecting previously unselected package qemu-guest-agent. (Reading database ... 108782 files and directories currently installed.) Preparing to unpack .../qemu-guest-agent_1%3a6.2+dfsg-2ubuntu6.2_amd64.deb ... Unpacking qemu-guest-agent (1:6.2+dfsg-2ubuntu6.2) ... Setting up qemu-guest-agent (1:6.2+dfsg-2ubuntu6.2) ... Processing triggers for man-db (2.10.2-1) ... Scanning processes... Scanning linux images... Running kernel seems to be up-to-date. No services need to be restarted. No containers need to be restarted. No user sessions are running outdated binaries. No VM guests are running outdated hypervisor (qemu) binaries on this host.
Inspect service status.
milosz@jammy:~$ systemctl status qemu-guest-agent.service
○ qemu-guest-agent.service - QEMU Guest Agent Loaded: loaded (/lib/systemd/system/qemu-guest-agent.service; static) Active: inactive (dead)
Reboot virtual machine.
milosz@jammy:~$ sudo reboot
Inspect service status after reboot.
milosz@jammy:~$ systemctl status qemu-guest-agent.service
● qemu-guest-agent.service - QEMU Guest Agent Loaded: loaded (/lib/systemd/system/qemu-guest-agent.service; static) Active: active (running) since Tue 2022-07-12 18:53:18 UTC; 19s ago Main PID: 638 (qemu-ga) Tasks: 2 (limit: 2241) Memory: 1.1M CPU: 22ms CGroup: /system.slice/qemu-guest-agent.service └─638 /usr/sbin/qemu-ga Jul 12 18:53:18 jammy systemd[1]: Started QEMU Guest Agent. Jul 12 18:53:25 jammy qemu-ga[638]: info: guest-ping called Jul 12 18:53:36 jammy qemu-ga[638]: info: guest-ping called
Execute Qemu Guest Agent command to test communication.
proxmox$ qm agent 3003 ping