On the main menu of ZStack Cloud, choose Resource Center > Resource Pool > Compute Configuration > Image. On the Image page, click Add Image. Then, the Add Image page is displayed.

Note: The x86_64 edition requires x86-64-v3. Select a host and VM CPU mode that meet this requirement.

Create a VM instance in ZStack Cloud and boot it from the installation image. For details, see the Create a VM Instance section in the User Guide. This example uses 2 vCPUs, 4 GiB memory, and a 40 GiB root volume. Use the same boot mode as the installation image.

The boot ISO downloads installation packages over the network. The installation NIC must be able to access the BaseOS and AppStream repositories. This verified example uses the CentOS Stream 10 BaseOS installation source at Tsinghua University TUNA. Verify DNS resolution and repository access, then wait for the installation source to load before selecting a minimal installation.

sudo hostnamectl set-hostname localhost.localdomain

This tutorial uses one Ethernet NIC with IPv4 DHCP. Select its connection UUID and clear source-specific static addresses, DNS settings, and NIC bindings. Changes are persistent by default.

nmcli -f NAME,UUID,TYPE,DEVICE connection show --active
PROFILE="REPLACE_WITH_CONNECTION_UUID"

sudo nmcli connection modify "$PROFILE" \
  connection.autoconnect yes connection.interface-name "" \
  ipv4.method auto ipv4.addresses "" ipv4.gateway "" \
  ipv4.routes "" ipv4.dns "" ipv4.dns-search "" \
  ipv4.ignore-auto-dns no ipv4.ignore-auto-routes no \
  ipv4.dhcp-client-id mac \
  802-3-ethernet.mac-address "" \
  802-3-ethernet.cloned-mac-address permanent

sudo nmcli connection up "$PROFILE"
nmcli device show

Note: Run these commands through the console because reactivating networking can interrupt SSH. Confirm that the DHCP-provided DNS works and disable obsolete autoconnect profiles.

sudo dnf install -y tar

Attach the GuestTools ISO from the source VM instance details page. Replace DEVICE with the actual optical device, such as /dev/sr0, and run the following commands. Resolve installation errors before continuing. If the media remains mounted, confirm that it is unused before unmounting it.

(
    set -e
    DEVICE="REPLACE_WITH_OPTICAL_DEVICE"
    test -b "$DEVICE"
    sudo mkdir -p /mnt/guesttools
    if mountpoint -q /mnt/guesttools; then
        printf '%s\n' 'Mount point already in use; inspect it before continuing.'
        exit 1
    fi
    sudo mount -o ro "$DEVICE" /mnt/guesttools
    test -f /mnt/guesttools/zs-tools-install.sh
    cd /mnt/guesttools
    sudo bash ./zs-tools-install.sh
    cd /
    sudo umount /mnt/guesttools
)

Note: The installer may report zs-tools is not verified for os: centos10. Confirm GuestTools support for the target release on your platform. Do not change distribution identifiers to bypass detection.

Install cloud-init if you need User Data or SSH public key initialization. Use root or an account with sudo privileges to install the following packages from the official repositories.

sudo dnf install -y cloud-init openssh-server &&
  sudo systemctl enable --now sshd

Retain SELinux and firewall policies. Add the following settings to /etc/cloud/cloud.cfg.d/99-template.cfg so that NetworkManager manages networking and cloud-init handles initialization. Merge changes if the file already exists.

network:
  config: disabled
preserve_hostname: false
ssh_deletekeys: true
ssh_pwauth: false

Note: SSH password authentication is disabled. Check the cloud-init default login user and provide an SSH public key for that user when creating VM instances from the image.

Save the changes and reboot the source VM instance.

sudo systemctl reboot

Remove temporary files, credentials in installation answer files, temporary accounts, and command history. Keep the login accounts and authentication settings required to use the image. cloud-init cleanup does not remove local account passwords.

If cloud-init is installed, confirm that it supports these cleanup options and is configured to generate SSH host keys on first boot as described above. Without cloud-init, the following commands only reset the machine ID, preserve the existing network configuration and SSH host keys, and shut down the VM instance. For images without cloud-init, arrange SSH host-key regeneration separately for each VM Instance.

sudo bash <<'CLEANUP'
set -e
if command -v cloud-init >/dev/null 2>&1; then
    cloud-init clean --logs --machine-id --seed
    rm -f /etc/ssh/ssh_host_*_key /etc/ssh/ssh_host_*_key.pub
else
    truncate -s 0 /etc/machine-id
fi
if [ -d /var/lib/dbus ]; then
    rm -f /var/lib/dbus/machine-id
    ln -s /etc/machine-id /var/lib/dbus/machine-id
fi
sync
systemctl poweroff
CLEANUP

Note: Run only on the template source VM instance. Resolve cleanup errors before proceeding. Do not restart the source after cleanup; if restarted, repeat cleanup before creating the image.

Confirm that the VM instance is stopped and detach the installation ISO and GuestTools ISO.

On the details page of the VM instance created, choose Actions > Image and ISO > Create Image. Then, the Create Image page is displayed.