Installing the guest environment

Linux VMs Windows VMs

---

This page describes how to manually install the guest environment for virtual machine (VM) instances that are running custom images on Compute Engine.

In most cases, if you are using VMs that are created using Google-provided public images, you do not need to install a guest environment. For information on when to use the guest environment, see When to manually install or update the guest environment.

Before you manually install the guest environment, use the Validate the guest environment procedure to check if the guest environment is running on your VM. If the guest environment is available on your VM but is outdated, update the guest environment.

Before you begin

If you want to use the gcloud command-line tool examples in this guide:
1. You can either install local tools or use Cloud Shell.
   • Use local tools
     • Install the gcloud command-line tool.
     • Install the jq command-line JSON processor: you can use this processor to filter gcloud output.
   • Use Cloud Shell, which has the gcloud tool and jq pre-installed: Open Cloud Shell
2. Set default properties.

   • gcloud config set compute/zone ZONE

   • gcloud config set compute/region REGION

   • gcloud config set project PROJECT

Installation methods

There are multiple ways that you can install the guest environment. Choose one of the following options:

• Import tool. This is the recommended option. However, keep in mind that the import tool not only installs the guest environment but does other configuration updates as well on the image such as configuring networks, configuring bootloader, and installing gcloud command-line tool. For instructions on how to use the import tool, review Making an image bootable.

  The import tool supports a wide variety of operating systems and versions. For more information, see operating system details.

• Manual installation. Choose one of the following:

  • Connect to your instance using SSH or RDP and install the guest environment in-place
  • Clone your boot disk and install the guest environment using a startup script

  Manual installation of the guest environment is available for the following operating systems:

  • Ubuntu 16.04 or later
  • CentOS 7 or later
  • SUSE Linux Enterprise Server (SLES) 12 SP4 or later and 15 SP1 or later
  • Red Hat Enterprise Linux (RHEL) 7 or later
  • Debian 9 or later
  • Windows Server 2019
  • Windows Server 2016
  • Windows Server 2012 R2
  • Windows Server Semi Annual Channel Releases
  • SQL Server on Windows Server
  • Windows bring your own license:
    • Windows 8
    • Windows 10

Limitations

You can't manually install or use the import tool to install guest environments for Fedora CoreOS and Container-optimized operating systems. If you need one of these operating systems, we recommend that you use public images, because a guest environment is included as a core part of all public images.

Installing the guest environment

Install the guest environment in-place

Use this method to install the guest environment if you can connect to the target instance using SSH. If you can't connect to the instance to install the guest environment, you can instead install the guest environment by cloning its boot disk and using a startup script.

This procedure is useful for imported images if you can connect using SSH password-based authentication. It might also be used to reinstall the guest environment if you have at least one user account with functional key-based SSH.

CentOS/RHEL

1. Ensure that the version of your operating system is supported.

2. Determine the version of CentOS/RHEL, and create the source repo file, /etc/yum.repos.d/google-cloud.repo:

   OS_RELEASE_FILE="/etc/redhat-release"
   if [ ! -f $OS_RELEASE_FILE ]; then
     OS_RELEASE_FILE="/etc/centos-release"
   fi
   DIST=$(cat $OS_RELEASE_FILE | grep -o '[0-9].*' | awk -F'.' '{print $1}')
   sudo tee /etc/yum.repos.d/google-cloud.repo << EOM
   [google-cloud-compute]
   name=Google Cloud Compute
   baseurl=https://packages.cloud.google.com/yum/repos/google-compute-engine-el${DIST}-x86_64-stable
   enabled=1
   gpgcheck=1
   repo_gpgcheck=0
   gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg
         https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
   EOM
   

3. Update package lists:

   sudo yum makecache
   sudo yum updateinfo
   

4. Install the guest environment packages:

   sudo yum install -y google-compute-engine google-osconfig-agent
   

5. Restart the instance and inspect its console log to make sure the guest environment loads as it starts back up.

6. Verify that you can connect to the instance using SSH.

Debian

1. Ensure that the version of your operating system is supported.

2. Install the public repo GPG key:

   curl https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -

3. Determine the name of the Debian distro, and create the source list file, /etc/apt/sources.list.d/google-cloud.list:

   DIST=$(cat /etc/os-release | grep "VERSION=" | sed "s/\"\|(\|)\|VERSION=//g" \
   | awk '{print tolower($NF)}')
   sudo tee /etc/apt/sources.list.d/google-cloud.list << EOM
   deb http://packages.cloud.google.com/apt google-compute-engine-${DIST}-stable main
   deb http://packages.cloud.google.com/apt google-cloud-packages-archive-keyring-${DIST} main
   EOM
   

4. Update package lists:

   sudo apt update

5. Install the guest environment packages:

   sudo apt install -y google-cloud-packages-archive-keyring
   sudo apt install -y google-compute-engine google-osconfig-agent
   

6. Restart the instance and inspect its console log to make sure the guest environment loads as it starts back up.

7. Verify that you can connect to the instance using SSH.

Ubuntu

1. Ensure that the version of your operating system is supported.

2. Enable the Universe repository. Canonical publishes packages for its guest environment to the Universe repository.

   sudo apt-add-repository universe

3. Update package lists:

   sudo apt update

4. Install the guest environment packages:

   sudo apt install -y google-compute-engine google-osconfig-agent
   

5. Restart the instance and inspect its console log to make sure the guest environment loads as it starts back up.

6. Verify that you can connect to the instance using SSH.

SLES

1. Ensure that the version of your operating system is supported.

2. Activate the Public Cloud Module.

   product=$(sudo SUSEConnect --list-extensions | grep -o "sle-module-public-cloud.*")
   [[ -n "$product" ]] && sudo SUSEConnect -p "$product"
   

3. Update package lists:

   sudo zypper refresh

4. Install the guest environment packages:

   sudo zypper install -y google-guest-{agent,configs,oslogin} \
   google-osconfig-agent
   sudo systemctl enable /usr/lib/systemd/system/google-*
   

5. Restart the instance and inspect its console log to make sure the guest environment loads as it starts back up.

6. Verify that you can connect to the instance using SSH.

Windows

Before you begin, ensure that the version of your operating system is supported.

To install the Windows guest environment, run the following commands in an elevated PowerShell version 3.0 or higher prompt. The Invoke-WebRequest command in the instructions below requires a version of PowerShell higher than 3.0.

1. Download and install GooGet.

   [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12;
   Invoke-WebRequest https://github.com/google/googet/releases/download/v2.17.2/googet.exe -OutFile $env:temp\googet.exe;
   & "$env:temp\googet.exe" -root C:\ProgramData\GooGet -noconfirm install -sources `
   https://packages.cloud.google.com/yuck/repos/google-compute-engine-stable googet;
   Remove-Item "$env:temp\googet.exe"
   

   During installation GooGet adds content to the system environment. After installation completes, launch a new PowerShell console or provide the full path to the googet.exe file (C:\ProgramData\GooGet\googet.exe).

2. Open a new console and add the google-compute-engine-stable repository.

   googet addrepo google-compute-engine-stable https://packages.cloud.google.com/yuck/repos/google-compute-engine-stable

3. Install the core Windows guest environment packages.

   googet -noconfirm install google-compute-engine-windows `
   google-compute-engine-sysprep google-compute-engine-metadata-scripts `
   google-compute-engine-vss google-osconfig-agent
   

4. Install the optional Windows guest environment package.

   googet -noconfirm install google-compute-engine-auto-updater

   Using the googet command.

   To view available packages, run the googet available command.

   To view installed packages, run the googet installed command.

   To update to the latest package version, run the googet update command.

   To view additional commands, run googet help.

Clone boot disk and use startup script

Important: In this procedure, the term startup script refers to using a rc.local script. It does not refer to a startup script specified in the instance metadata. Instance metadata startup scripts depend on the guest environment, and cannot be used to install it.

If you cannot connect to an instance to manually install the guest environment, install the guest environment using this procedure, which includes the following steps that can be completed in the Google Cloud console or Cloud Shell.

This method shows the procedure for Linux distributions only. For Windows, use one of the other two installation methods.

Use the Cloud Shell to run this procedure:

CentOS/RHEL

1. Ensure that the version of your operating system is supported.

2. Create a new instance to serve as the rescue instance. Name this instance rescue. This rescue instance does not need to run the same Linux OS as the problematic instance. This example uses Debian 9 on the rescue instance.

3. Stop the problematic instance and create a copy of its boot disk.

   1. Set a variable name for the problematic instance. This makes it easier to reference the instance in later steps.

      export PROB_INSTANCE_NAME=VM_NAME

      Replace VM_NAME with the name of the problematic instance.

   2. Stop the problematic instance.

      gcloud compute instances stop "$PROB_INSTANCE_NAME"

   3. Get the name of the boot disk for the problem instance.

      export PROB_INSTANCE_DISK="$(gcloud compute instances describe \
      "$PROB_INSTANCE_NAME" --format='json' |  jq -r \
      '.disks[] | select(.boot == true) | .source')"
      

   4. Create a snapshot of the boot disk.

      export DISK_SNAPSHOT="${PROB_INSTANCE_NAME}-snapshot"
      
      gcloud compute disks snapshot "$PROB_INSTANCE_DISK" \
         --snapshot-names "$DISK_SNAPSHOT"
      

   5. Create a new disk from the snapshot.

      export NEW_DISK="${PROB_INSTANCE_NAME}-new-disk"
      
      gcloud compute disks create "$NEW_DISK" \
         --source-snapshot="$DISK_SNAPSHOT"
      

   6. Delete the snapshot:

      gcloud compute snapshots delete "$DISK_SNAPSHOT"

4. Attach the new disk to the rescue instance and mount the root volume for the rescue instance. Because this procedure only attaches one additional disk, the device identifier of the new disk is /dev/sdb. CentOS/RHEL uses the first volume on a disk as the root volume by default, so the volume identifier should be /dev/sdb1. For custom cases, use lsblk to determine the volume identifier.

   gcloud compute instances attach-disk rescue --disk "$NEW_DISK"

5. Connect to the rescue instance using SSH:

   gcloud compute ssh rescue

6. Run the following steps on the rescue instance.

   1. Mount the root volume of the new disk.

      export NEW_DISK_MOUNT_POINT="/tmp/sdb-root-vol"
      DEV="/dev/sdb1"
      sudo mkdir "$NEW_DISK_MOUNT_POINT"
      sudo mount "$DEV" "$NEW_DISK_MOUNT_POINT"
      if [ "$?" != "0" ]; then
      # Handle XFS filesystem cases (CentOS/RHEL 7):
      sudo mount -o nouuid "$DEV" "$NEW_DISK_MOUNT_POINT"
      fi
      

   2. Create the rc.local script.

      cat <<'EOF' >/tmp/rc.local
      #!/bin/bash
      YUM_SERVER="packages.cloud.google.com"
      REPO_FILE="/etc/yum.repos.d/google-cloud.repo"
      echo "== Installing a Linux guest environment for CentOS/RHEL =="
      sleep 30 # Wait for network.
      echo "Determining CentOS/RHEL version..."
      OS_RELEASE_FILE="/etc/redhat-release"
      if [ ! -f "$OS_RELEASE_FILE" ]; then
        OS_RELEASE_FILE="/etc/centos-release"
      fi
      if [ ! -f "$OS_RELEASE_FILE" ]; then
        echo "ERROR: This system does not appear to be CentOS/RHEL."
        exit 1
      fi
      DIST=$(cat "$OS_RELEASE_FILE" | grep -o '[0-9].*' | awk -F'.' '{print $1}')
      if [ -z $DIST ]; then
        echo "ERROR: Could not determine version of CentOS/RHEL."
        exit 1
      fi
      echo "Updating $REPO_FILE..."
      tee "$REPO_FILE" << EOM
      [google-cloud-compute]
      name=Google Cloud Compute
      baseurl=https://$YUM_SERVER/yum/repos/google-compute-engine-el${DIST}-x86_64-stable
      enabled=1
      gpgcheck=1
      repo_gpgcheck=0
      gpgkey=https://$YUM_SERVER/yum/doc/yum-key.gpg
      https://$YUM_SERVER/yum/doc/rpm-package-key.gpg
      EOM
      echo "Running yum makecache..."
      yum makecache
      echo "Running yum updateinfo..."
      yum updateinfo
      echo "Running yum install google-compute-engine..."
      yum install -y google-compute-engine
      if [ "$?" != "0" ]; then
        echo "ERROR: Failed to install ${pkg}."
      fi
      echo "Removing this rc.local script."
      rm /etc/rc.d/rc.local
      # Move back any previous rc.local:
      if [ -f "/etc/moved-rc.local" ]; then
        echo "Restoring a previous rc.local script."
        mv "/etc/moved-rc.local" "/etc/rc.d/rc.local"
      fi
      echo "Restarting the instance..."
      reboot now
      EOF
      

   3. Move the rc.local script to the root volume of the new disk and set permissions. Move any existing rc.local script aside. The temporary script will replace it when it finishes.

      if [ -f "$NEW_DISK_MOUNT_POINT/etc/rc.d/rc.local" ]; then
        sudo mv "$NEW_DISK_MOUNT_POINT/etc/rc.d/rc.local" \
        "$NEW_DISK_MOUNT_POINT/etc/moved-rc.local"
      fi
      sudo mv /tmp/rc.local "$NEW_DISK_MOUNT_POINT/etc/rc.d/rc.local"
      sudo chmod 0755 "$NEW_DISK_MOUNT_POINT/etc/rc.d/rc.local"
      sudo chown root:root "$NEW_DISK_MOUNT_POINT/etc/rc.d/rc.local"
      

   4. Un-mount the root volume of the new disk.

      sudo umount "$NEW_DISK_MOUNT_POINT" && sudo rmdir \
      "$NEW_DISK_MOUNT_POINT"

   5. Exit the SSH session to the rescue instance.

7. Detach the new disk from the rescue instance.

   gcloud compute instances detach-disk rescue --disk "$NEW_DISK"

8. Create an instance to serve as the replacement. When you create the replacement instance, specify the new disk as the boot disk. You can create the replacement instance using the Google Cloud Console:

   1. In the Google Cloud Console, go to the VM instances page.

      Go to VM instances

   2. Click the problematic instance, then click Create similar.

   3. Specify a name for the replacement instance. In the Boot disk section, click Change, then click Existing Disks. Select the new disk.

   4. Click Create. The replacement instance automatically starts after it is created.

   As the replacement instance start up, the temporary rc.local script runs and installs the guest environment. To watch the progress of this script, inspect the console logs for lines emitted by the temporary rc.local script. To view logs, run the following command:

   gcloud compute instances get-serial-port-output REPLACEMENT_VM_NAME

   Replace REPLACEMENT_VM_NAME with the name you assigned the replacement instance.

   The replacement instance also automatically reboots when the temporary rc.local script finishes. During the second reboot, you can inspect the console log to make sure the guest environment loads.

9. Verify that you can connect to the instance using SSH.

   When you are satisfied that the replacement instance is functional, you can stop or delete the problematic instance.

Debian

1. Ensure that the version of your operating system is supported

2. Create a new instance to serve as the rescue instance. Name this instance rescue. This rescue instance does not need to run the same Linux OS as the problematic instance. This example uses Debian 9 on the rescue instance.

3. Stop the problematic instance and create a copy of its boot disk.

   1. Set a variable name for the problematic instance. This makes it easier to reference the instance in later steps.

      export PROB_INSTANCE_NAME=VM_NAME

      Replace VM_NAME with the name of the problematic instance.

   2. Stop the problematic instance.

      gcloud compute instances stop "$PROB_INSTANCE_NAME"

   3. Get the name of the boot disk for the problem instance.

      export PROB_INSTANCE_DISK="$(gcloud compute instances describe \
      "$PROB_INSTANCE_NAME" --format='json' |  jq -r \
      '.disks[] | select(.boot == true) | .source')"
      

   4. Create a snapshot of the boot disk.

      export DISK_SNAPSHOT="${PROB_INSTANCE_NAME}-snapshot"
      
      gcloud compute disks snapshot "$PROB_INSTANCE_DISK" \
         --snapshot-names "$DISK_SNAPSHOT"
      

   5. Create a new disk from the snapshot.

      export NEW_DISK="${PROB_INSTANCE_NAME}-new-disk"
      
      gcloud compute disks create "$NEW_DISK" \
         --source-snapshot="$DISK_SNAPSHOT"
      

   6. Delete the snapshot:

      gcloud compute snapshots delete "$DISK_SNAPSHOT"

4. Attach the new disk to the rescue instance and mount the root volume for the rescue instance. Because this procedure only attaches one additional disk, the device identifier of the new disk is /dev/sdb. Debian uses the first volume on a disk as the root volume by default, so the volume identifier should be /dev/sdb1. For custom cases, use lsblk to determine the volume identifier.

   gcloud compute instances attach-disk rescue --disk "$NEW_DISK"

5. Connect to the rescue instance using SSH:

   gcloud compute ssh rescue

6. Run the following steps on the rescue instance.

   1. Mount the root volume of the new disk.

      export NEW_DISK_MOUNT_POINT="/tmp/sdb-root-vol"
      DEV="/dev/sdb1"
      sudo mkdir "$NEW_DISK_MOUNT_POINT"
      sudo mount "$DEV" "$NEW_DISK_MOUNT_POINT"
      

   2. Create the rc.local script.

      cat <<'EOF' >/tmp/rc.local
      #!/bin/bash
      declare -x APT_SERVER="packages.cloud.google.com"
      declare -x REPO_FILE="/etc/apt/sources.list.d/google-cloud.list"
      echo "== Installing a Linux guest environment for Debian =="
      sleep 30 # Wait for network.
      echo "Determining Debian version..."
      DIST=$(cat /etc/os-release | grep "VERSION=" \
      | sed "s/\"\|(\|)\|VERSION=//g" | awk '{print tolower($NF)}')
      if [ -z $DIST ]; then
       echo "ERROR: Could not determine Debian version."
       exit 1
      fi
      echo "Adding GPG key for $APT_SERVER."
      curl https://$APT_SERVER/apt/doc/apt-key.gpg | apt-key add -
      echo "Updating $REPO_FILE..."
      tee "$REPO_FILE" << EOM
      deb http://$APT_SERVER/apt google-compute-engine-${DIST}-stable main
      deb http://$APT_SERVER/apt google-cloud-packages-archive-keyring-${DIST} main
      EOM
      echo "Running apt update..."
      apt update
      echo "Installing packages..."
      for pkg in google-cloud-packages-archive-keyring google-compute-engine; do
       echo "Running apt install ${pkg}..."
       apt install -y ${pkg}
       if [ "$?" != "0" ]; then
          echo "ERROR: Failed to install ${pkg}."
       fi
      done
      echo "Removing this rc.local script."
      rm /etc/rc.local
      # Move back any previous rc.local:
      if [ -f "/etc/moved-rc.local" ]; then
       echo "Restoring a previous rc.local script."
       mv "/etc/moved-rc.local" "/etc/rc.local"
      fi
      echo "Restarting the instance..."
      reboot now
      EOF
      

   3. Move the rc.local script to the root volume of the new disk and set permissions. Move any existing rc.local script aside. The temporary script will replace it when it finishes.

      if [ -f "$NEW_DISK_MOUNT_POINT/etc/rc.local" ]; then
         sudo mv "$NEW_DISK_MOUNT_POINT/etc/rc.local" \
         "$NEW_DISK_MOUNT_POINT/etc/moved-rc.local"
      fi
      sudo mv /tmp/rc.local "$NEW_DISK_MOUNT_POINT/etc/rc.local"
      sudo chmod 0755 "$NEW_DISK_MOUNT_POINT/etc/rc.local"
      sudo chown root:root "$NEW_DISK_MOUNT_POINT/etc/rc.local"
      

   4. Un-mount the root volume of the new disk.

      sudo umount "$NEW_DISK_MOUNT_POINT" && sudo rmdir "$NEW_DISK_MOUNT_POINT"

   5. Exit the SSH session to the rescue instance.

7. Detach the new disk from the rescue instance.

   gcloud compute instances detach-disk rescue --disk "$NEW_DISK"

8. Create a new instance to serve as the replacement. When you create the replacement instance, specify the new disk as the boot disk. You can create the replacement instance using the Google Cloud Console:

   1. In the Google Cloud Console, go to the VM instances page.

      Go to VM instances

   2. Click the problematic instance, then click Create similar.

   3. Specify a name for the replacement instance. In the Boot disk section, click Change, then click Existing Disks. Select the new disk.

   4. Click Create. The replacement instance automatically starts after it is created.

   As the replacement instance start up, the temporary rc.local script runs and installs the guest environment. To watch the progress of this script, inspect the console logs for lines emitted by the temporary rc.local script. To view logs, run the following command:

   gcloud compute instances get-serial-port-output REPLACEMENT_VM_NAME

   Replace REPLACEMENT_VM_NAME with the name you assigned the replacement instance.

   The replacement instance also automatically reboots when the temporary rc.local script finishes. During the second reboot, you can inspect the console log to make sure the guest environment loads.

9. Verify that you can connect to the instance using SSH.

   When you are satisfied that the replacement instance is functional, you can stop or delete the problematic instance.

Ubuntu

1. Ensure that the version of your operating system is supported

2. Create a new instance to serve as the rescue instance. Name this instance rescue. This rescue instance does not need to run the same Linux OS as the problematic instance. This example uses Debian 9 on the rescue instance.

3. Stop the problematic instance and create a copy of its boot disk.

   1. Set a variable name for the problematic instance. This makes it easier to reference the instance in later steps.

      export PROB_INSTANCE_NAME=VM_NAME

      Replace VM_NAME with the name of the problematic instance.

   2. Stop the problematic instance.

      gcloud compute instances stop "$PROB_INSTANCE_NAME"

   3. Get the name of the boot disk for the problem instance.

      export PROB_INSTANCE_DISK="$(gcloud compute instances describe \
      "$PROB_INSTANCE_NAME" --format='json' |  jq -r \
      '.disks[] | select(.boot == true) | .source')"
      

   4. Create a snapshot of the boot disk.

      export DISK_SNAPSHOT="${PROB_INSTANCE_NAME}-snapshot"
      
      gcloud compute disks snapshot "$PROB_INSTANCE_DISK" \
         --snapshot-names "$DISK_SNAPSHOT"
      

   5. Create a new disk from the snapshot.

      export NEW_DISK="${PROB_INSTANCE_NAME}-new-disk"
      
      gcloud compute disks create "$NEW_DISK" \
         --source-snapshot="$DISK_SNAPSHOT"
      

   6. Delete the snapshot:

      gcloud compute snapshots delete "$DISK_SNAPSHOT"

4. Attach the new disk to the rescue instance and mount the root volume for the rescue instance. Because this procedure only attaches one additional disk, the device identifier of the new disk is /dev/sdb. Ubuntu labels its root volume 1 by default, so the volume identifier should be /dev/sdb1. For custom cases, use lsblk to determine the volume identifier.

   gcloud compute instances attach-disk rescue --disk "$NEW_DISK"

5. Connect to the rescue instance using SSH:

   gcloud compute ssh rescue

6. Run the following steps on the rescue instance.

   1. Mount the root volume of the new disk.

      export NEW_DISK_MOUNT_POINT="/tmp/sdb-root-vol"
      DEV="/dev/sdb1"
      sudo mkdir "$NEW_DISK_MOUNT_POINT"
      sudo mount "$DEV" "$NEW_DISK_MOUNT_POINT"
      

   2. Create the rc.local script.

      cat <<'EOF' >/tmp/rc.local
      #!/bin/bash
      echo "== Installing a Linux guest environment for Ubuntu =="
      sleep 30 # Wait for network.
      echo "Running apt update..."
      apt update
      echo "Installing packages..."
      echo "Running apt install google-compute-engine..."
      apt install -y google-compute-engine
      if [ "$?" != "0" ]; then
       echo "ERROR: Failed to install ${pkg}."
      fi
      echo "Removing this rc.local script."
      rm /etc/rc.local
      # Move back any previous rc.local:
      if [ -f "/etc/moved-rc.local" ]; then
       echo "Restoring a previous rc.local script."
       mv "/etc/moved-rc.local" "/etc/rc.local"
      fi
      echo "Restarting the instance..."
      reboot now
      EOF
      

   3. Move the rc.local script to the root volume of the new disk and set permissions. Move any existing rc.local script aside. The temporary script will replace it when it finishes.

      if [ -f "$NEW_DISK_MOUNT_POINT/etc/rc.local" ]; then
         sudo mv "$NEW_DISK_MOUNT_POINT/etc/rc.local" \
         "$NEW_DISK_MOUNT_POINT/etc/moved-rc.local"
      fi
      sudo mv /tmp/rc.local "$NEW_DISK_MOUNT_POINT/etc/rc.local"
      sudo chmod 0755 "$NEW_DISK_MOUNT_POINT/etc/rc.local"
      sudo chown root:root "$NEW_DISK_MOUNT_POINT/etc/rc.local"
      

   4. Un-mount the root volume of the new disk.

      sudo umount "$NEW_DISK_MOUNT_POINT" && sudo rmdir "$NEW_DISK_MOUNT_POINT"

   5. Exit the SSH session to the rescue instance.

7. Detach the new disk from the rescue instance.

   gcloud compute instances detach-disk rescue --disk "$NEW_DISK"

8. Create a new instance to serve as the replacement. When you create the replacement instance, specify the new disk as the boot disk. You can create the replacement instance using the Google Cloud Console:

   1. In the Google Cloud Console, go to the VM instances page.

      Go to VM instances

   2. Click the problematic instance, then click Create similar.

   3. Specify a name for the replacement instance. In the Boot disk section, click Change, then click Existing Disks. Select the new disk.

   4. Click Create. The replacement instance automatically starts after it is created.

   As the replacement instance start up, the temporary rc.local script runs and installs the guest environment. To watch the progress of this script, inspect the console logs for lines emitted by the temporary rc.local script. To view logs, run the following command:

   gcloud compute instances get-serial-port-output REPLACEMENT_VM_NAME

   Replace REPLACEMENT_VM_NAME with the name you assigned the replacement instance.

   The replacement instance also automatically reboots when the temporary rc.local script finishes. During the second reboot, you can inspect the console log to make sure the guest environment loads.

9. Verify that you can connect to the instance using SSH.

   When you are satisfied that the replacement instance is functional, you can stop or delete the problematic instance.

Updating the guest environment

If you are getting a message that the guest environment is outdated, update the packages for your operating system.

CentOS/RHEL

To update CentOS and RHEL operating systems, run the following commands:

sudo yum makecache
sudo yum install google-compute-engine google-compute-engine-oslogin \
google-guest-agent google-osconfig-agent

Debian

To update Debian operating systems, run the following commands:

sudo apt update
sudo apt install google-compute-engine google-compute-engine-oslogin \
google-guest-agent google-osconfig-agent

Ubuntu

To update Ubuntu operating systems, run the following commands:

sudo apt update
sudo apt install google-compute-engine google-compute-engine-oslogin \
google-guest-agent google-osconfig-agent

SLES

To update SLES operating systems, run the following commands:

sudo zypper refresh
sudo zypper install google-guest-{agent,configs,oslogin} \
google-osconfig-agent

Windows

To update Windows operating systems, run the following command:

googet update

Validating the guest environment

The presence of a guest environment can be determined by either inspecting system logs emitted to the console while an instance starts up, or by listing the installed packages while connected to the instance.

Expected console logs for the guest environment

This table summarizes expected output for console logs emitted by instances with working guest environments as they start up.

Operating system	Service management	Expected output
CentOS/RHEL Debian Ubuntu SLES Container-Optimized OS 89 and newer	systemd	GCEGuestAgent Info: GCE Agent Started (version YYYYMMDD.NN) GCEMetadataScripts: Starting startup scripts (version YYYYMMDD.NN) OSConfigAgent Info: OSConfig Agent (version YYYYMMDD.NN)
Container-Optimized OS 85 and older	systemd	Started Google Compute Engine Accounts Daemon Started Google Compute Engine Network Daemon Started Google Compute Engine Clock Skew Daemon Started Google Compute Engine Instance Setup Started Google Compute Engine Startup Scripts Started Google Compute Engine Shutdown Scripts
Windows		GCEGuestAgent: GCE Agent Started (version YYYYMMDD.NN) GCEMetadataScripts: Starting startup scripts (version YYYYMMDD.NN) OSConfigAgent Info: OSConfig Agent (version YYYYMMDD.NN)

To view console logs for an instance, follow these steps.

Console

1. In the Google Cloud Console, go to the VM instances page.

   Go to VM instances

   1. Click the instance you need to examine.
   2. Restart or reset the instance.
   3. Under Logs, click Serial port 1 (console).
   4. Search for the expected output referencing the table above.

gcloud

1. Restart or reset the instance.

2. Use the gcloud compute instances get-serial-port-output subcommand to connect using the gcloud command-line tool. For example:

   gcloud compute instances get-serial-port-output VM_NAME

   Replace VM_NAME with the name of the instance you need to examine.

3. Search for the expected output referencing the table above.

Loaded services for the guest environment

This table summarizes the services that should be loaded on instances with working guest environments. The command to list services must be run after connecting to the instance, so this check can only be performed if you have access to it.

Operating system	Command to list services	Expected output
CentOS/RHEL Debian	sudo systemctl list-unit-files \ | grep google | grep enabled	google-disk-expand.service enabled google-guest-agent.service enabled google-osconfig-agent.service enabled google-shutdown-scripts.service enabled google-startup-scripts.service enabled google-oslogin-cache.timer enabled
Ubuntu	sudo systemctl list-unit-files \ | grep google | grep enabled	google-guest-agent.service enabled google-osconfig-agent.service enabled google-shutdown-scripts.service enabled google-startup-scripts.service enabled google-oslogin-cache.timer enabled
Container-Optimized OS	sudo systemctl list-unit-files \ | grep google	var-lib-google.mount disabled google-accounts-daemon.service disabled google-clock-skew-daemon.service disabled google-instance-setup.service disabled google-ip-forwarding-daemon.service disabled google-network-setup.service disabled google-shutdown-scripts.service disabled google-startup-scripts.service disabled var-lib-google-remount.service static
SLES 12+	sudo systemctl list-unit-files \ | grep google | grep enabled	google-guest-agent.service enabled google-osconfig-agent.service enabled google-shutdown-scripts.service enabled google-startup-scripts.service enabled google-oslogin-cache.timer enabled
Windows	Get-Service GCEAgent Get-ScheduledTask GCEStartup	Running GCEAgent GCEAgent \ GCEStartup Ready

Installed packages for the guest environment

This table summarizes the packages that should be installed on instances with working guest environments. The command to list installed packages must be run after connecting to the instance, so this check can only be performed if you have access to it.

Note: CoreOS and Container-Optimized OS do not have package managers. Inspect instance console logs or loaded services to determine the status of the guest environment instead.

Operating system	Command to list packages	Expected output
CentOS/RHEL	rpm -qa --queryformat '%{NAME}\n' \ |grep -iE google\|gce | grep -iE \ 'google|gce'	google-osconfig-agent google-compute-engine-oslogin google-guest-agent gce-disk-expand google-cloud-sdk google-compute-engine
Debian	apt list --installed \ | grep -iE 'google'	gce-disk-expand google-cloud-packages-archive-keyring google-cloud-sdk google-compute-engine-oslogin google-compute-engine google-guest-agent google-osconfig-agent
Ubuntu	apt list --installed \ | grep -iE "google"	google-compute-engine-oslogin google-compute-engine google-guest-agent google-osconfig-agent
SUSE (SLES)	rpm -qa --queryformat '%{NAME}\n' \ |grep -iE google	google-guest-configs google-osconfig-agent google-guest-oslogin google-guest-agent
Windows	googet installed	certgen googet google-compute-engine-auto-updater google-compute-engine-driver-gga google-compute-engine-driver-netkvm google-compute-engine-driver-pvpanic google-compute-engine-driver-vioscsi google-compute-engine-metadata-scripts google-compute-engine-powershell google-compute-engine-sysprep google-compute-engine-vss google-compute-engine-windows google-osconfig-agent

What's next

• Read the troubleshooting tips.
• Learn more about applying metadata.
• Learn about SSH keys.