Import qcow2 cloud image to ESXi

I’m attempting to configure CentOS Stream 9 on ESXi using a cloud image.

However, the cloud image is not available in VMDK format, and the ISO file is quite large at 9GB.

I’d prefer not to install the VM from the ISO.

Instead, I plan to convert the QCOW2 image to VMDK format and then import it into ESXi. To begin, I need to download the QCOW2 cloud image: https://cloud.centos.org/centos/9-stream/x86_64/images/

I followed the steps outlined in this guide (https://blog.ktz.me/migrate-qcow2-images-from-kvm-to-vmware/) to convert a VMDK from a QCOW2 image:

1. Use the qemu-img tool to convert the QCOW2 image to a VMDK format:

qemu-img convert -f qcow2 -O vmdk quassel.qcow2 quasselog.vmdk

2. Copy the resulting VMDK file to ESXi.

3. In ESXi, create a VM with no disk attached.

4. Perform an additional conversion of the VMDK file to a ESXi-compatible format using vmkfstools:

vmkfstools -i quasselog.vmdk -d thin quassel.vmdk

5. After this conversion, I got two files. Copy both of them to the VM’s datastore.

6. Edit the VM’s settings, add a new disk, and select the option to use an existing disk. Choose the converted VMDK file to attach it to the VM.

The cloud image does not automatically assign a default linux account / password, leaving us with no means to access the system.

There are two methods available for logging into the VM:

1. Use cloud-init to configure the network and user
2. Set a default root password within the QCOW2 image

Method1:

Start by creating a user-data file:

vim user-data

#cloud-config
users:
  - name: centos
    plain_text_passwd: centos
    groups: sudo
    sudo: ALL=(ALL) NOPASSWD:ALL
    shell: /bin/bash
    lock_passwd: false

See more on cloud-init User-Data Examples.

Next, convert the user-data file to base64 encoding:

base64 user-data

In ESXi, modify the VM’s settings:

• Navigate to Configuration Parameters.
• Add the following parameters:

guestinfo.userdata.encoding: base64
guestinfo.userdata: <base64 encoded user-data>

Include the network configuration

network:
  version: 2
  ethernets:
    eth1:
      dhcp4: false
      dhcp6: false
      addresses:
        - 192.168.0.100/24
      gateway4: 192.168.0.100
      nameservers:
        addresses:
          - 8.8.8.8

See more on cloud-init Network Config Format v2 Examples.

Finally, add this data to the guestinfo.metadata to the Configuration Parameters.

See more on cloud-init VMware Data Source.

Method2:

virt-customize -a centos.qcow2 --root-password password:<password>

See more on Use libguestfs to manage virtual machine disk images