Solo se puede ejecutar por la via rapida la instalacion de qemu-agent para estos custro PERO desde la maquina distrobuilder:
- virt-customize --install qemu-guest-agent -a CentOS-6-x86_64-GenericCloud.qcow2
- virt-customize --install qemu-guest-agent -a CentOS-7-x86_64-GenericCloud.qcow2
- virt-customize --install qemu-guest-agent -a CentOS-8-GenericCloud-8.4.2105-20210603.0.x86_64.qcow2
- virt-customize --install qemu-guest-agent -a CentOS-Stream-GenericCloud-x86_64-9-latest.x86_64.qcow2
En el caso de CentOS-8-GenericCloud-8.4.2105-20210603.0.x86_64.qcow2 y CentOS-Stream-GenericCloud-8-latest.x86_64.qcow2 hay que cambiar las urls de los repos antes


Estos otros dos se hacen desde el Cluste de proxmox haciendo:
- virt-customize --install qemu-guest-agent -a CentOS-Stream-GenericCloud-8-latest.x86_64.qcow2
- virt-customize -a CentOS-8-GenericCloud-8.4.2105-20210603.0.x86_64.qcow2 --run-command 'systemctl enable qemu-guest-agent'
- virt-customize --install openssh-server -a CentOS-Stream-GenericCloud-8-latest.x86_64.qcow2
- virt-customize -a CentOS-Stream-GenericCloud-8-latest.x86_64.qcow2 --run-command 'systemctl enable sshd'


guestmount -a CentOS-8-GenericCloud-8.4.2105-20210603.0.x86_64.qcow2 -m /dev/sda1 /mnt/images
sed -i 's|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g' /mnt/images/etc/yum.repos.d/CentOS-*
sed -i 's/mirrorlist/#mirrorlist/g' /mnt/images/etc/yum.repos.d/CentOS-*
guestunmount /mnt/images

virt-customize --install qemu-guest-agent -a CentOS-8-GenericCloud-8.4.2105-20210603.0.x86_64.qcow2
[   0.0] Examining the guest ...
[   7.6] Setting a random seed
[   7.7] Installing packages: qemu-guest-agent
[  20.4] Finishing off
virt-customize --install openssh-server -a CentOS-8-GenericCloud-8.4.2105-20210603.0.x86_64.qcow2
[   0.0] Examining the guest ...
[   7.7] Setting a random seed
[   7.8] Installing packages: openssh-server
[  14.1] Finishing off
virt-customize -a CentOS-8-GenericCloud-8.4.2105-20210603.0.x86_64.qcow2 --run-command 'systemctl enable qemu-guest-agent'
[   0.0] Examining the guest ...
[   7.6] Setting a random seed
[   7.7] Running: systemctl enable qemu-guest-agent
[   8.1] Finishing off
virt-customize -a CentOS-8-GenericCloud-8.4.2105-20210603.0.x86_64.qcow2 --run-command 'systemctl enable sshd'
[   0.0] Examining the guest ...
[   7.0] Setting a random seed
[   7.1] Running: systemctl enable sshd
[   7.5] Finishing off