Manual deployment: SAP HANA scale-out with host auto-failover on SLES

The instructions in this guide use a Terraform configuration provided by Google Cloud to automate the deployment of the resources required for this system. This Terraform configuration lets you deploy resources in a way that helps you meet SAP support requirements and adhere to SAP and Google Cloud best practices.

This guide is intended for advanced SAP HANA users who are familiar with SAP scale-out configurations that include standby hosts for high availability, as well as network file systems.

System that this guide deploys

The resulting SAP HANA system includes the following components:

• A master host, up to 15 worker hosts, and up to 3 standby hosts, all within a single Compute Engine zone.
• The storage manager for SAP HANA (gceStorageClient), which manages the transfer of storage devices from the faulty node to the standby node during failover events. This tool is installed in the /hana/shared directory. For more information about storage manager for SAP HANA, see The storage manager for SAP HANA.

Before you begin

Before you deploy your SAP HANA scale-out system, make sure that the following prerequisites are met:

• You have read the SAP HANA planning guide and the SAP HANA high-availability planning guide.
• You or your organization has a Google Cloud account and you have created a project for the SAP HANA deployment. For more information, see Setting up your Google account.
• If you require your SAP workload to run in compliance with data residency, access control, support personnel, or regulatory requirements, then you must create the required Assured Workloads folder. For more information, see Compliance and sovereign controls for SAP on Google Cloud.

• You've set up an NFS solution, such as the managed Filestore solution, for sharing the SAP HANA /hana/shared and /hanabackup directories among the hosts in your scale-out system. You specify the mount points for the NFS servers in the Terraform configuration that you use for this deployment.

  For information about the file sharing solutions that you can use with SAP on Google Cloud, see File sharing solutions for SAP on Google Cloud. For information about how to deploy Filestore instances to run your NFS servers, see Create an instance.

• You've set up a new VPC subnetwork for this deployment and have set up firewall rules that allow communication between the compute instances that serve as nodes in your SAP HANA scale-out system. For more information, see the following:

  • Create a VPC network
  • Set up a Cloud NAT gateway
  • Add firewall rules

• You've verified that the terminal you're using has the Google Cloud CLI and Terraform CLI installed. For information about how to install the Terraform CLI, see Install Terraform.

• If OS login is enabled in your project metadata, then you need to disable OS login temporarily until your deployment is complete. For deployment purposes, this procedure configures SSH keys in instance metadata. When OS login is enabled, metadata-based SSH key configurations are disabled, and this deployment fails. After deployment is complete, you can enable OS login again.

  For more information, see:

  • Enabling or disabling OS Login
  • Add SSH keys to VMs that use metadata-based SSH keys

Create a VPC network

For security purposes, create a new network. You can control who has access by adding firewall rules or by using another access control method.

If your project has a default VPC network, then don't use it. Instead, create your own VPC network so that the only firewall rules in effect are those that you create explicitly.

During deployment, Compute Engine instances typically require access to the internet to download Google Cloud's Agent for SAP. If you are using one of the SAP-certified Linux images that are available from Google Cloud, then the compute instance also requires access to the internet in order to register the license and to access OS vendor repositories. A configuration with a NAT gateway and with VM network tags supports this access, even if the target compute instances don't have external IPs.

To create a VPC network for your project, complete the following steps:

1. Create a custom mode network. For more information, see Creating a custom mode network.

2. Create a subnetwork, and specify the region and IP range. For more information, see Adding subnets.

Set up a Cloud NAT gateway

If you need to create one or more compute instances without public IP addresses, then you need to use network address translation (NAT) to enable the instances to access the internet. Use Cloud NAT, a Google Cloud distributed, software-defined managed service that lets the compute instances send outbound packets to the internet and receive any corresponding established inbound response packets. Alternatively, you can set up a separate compute instance as a NAT gateway.

To create a Cloud NAT instance for your project, see Using Cloud NAT.

After you configure Cloud NAT for your project, your compute instances can securely access the internet without a public IP address.

Add firewall rules

By default, an implied firewall rule blocks incoming connections from outside your Virtual Private Cloud (VPC) network. To allow incoming connections, set up a firewall rule for your VM. After an incoming connection is established with a VM, traffic is permitted in both directions over that connection.

You can also create a firewall rule to allow external access to specified ports, or to restrict access between VMs on the same network. If the default VPC network type is used, some additional default rules also apply, such as the default-allow-internal rule, which allows connectivity between VMs on the same network on all ports.

Depending on the IT policy that is applicable to your environment, you might need to isolate or otherwise restrict connectivity to your database host, which you can do by creating firewall rules.

Depending on your scenario, you can create firewall rules to allow access for:

• The default SAP ports that are listed in TCP/IP of All SAP Products.
• Connections from your computer or your corporate network environment to your Compute Engine instance. If you are unsure of what IP address to use, talk to your company's network administrator.

To create the firewall rules for your project, see Creating firewall rules.

Deploy the SAP HANA scale-out system with the host auto-failover solution

In the following instructions, you complete the following actions:

• Deploy resources for SAP HANA by using a Terraform configuration file that you complete.
• Install SAP HANA by using gceStorageClient as the storage provider.
• Test the standby host by simulating a host failure.

Some of the steps in the following instructions use Cloud Shell to run the gcloud commands. If you have installed the latest version of gcloud CLI, then you can run the gcloud commands from a local terminal instead.

Set up a service account for the storage manager for SAP HANA

To enable host auto-failover for your SAP HANA scale-out system on Google Cloud, the storage manager for SAP HANA requires a service account. It is through this service account that the storage manager for SAP HANA performs actions such as detaching and attaching disks during a failover.

1. Create a service account. For information about how to do this, see Create a service account.

2. Grant the following IAM permissions to the service account:

   • compute.instances.reset permission: to reset a compute instance by running the gcloud compute instances reset command.
   • compute.disks.get permission: to get information about the Hyperdisk or Persistent Disk volumes by running the gcloud compute disks describe command.
   • compute.disks.list: to list the Hyperdisk and Persistent Disk volumes by using the gcloud compute disks list command.
   • compute.instances.attachDisk permission and iam.serviceAccounts.actAs: to attach a disk to a compute instance by running the gcloud compute instances attach-disk command.
   • compute.instances.detachDisk permission: to detach a disk from a compute instance by using the gcloud compute instances detach-disk command.
   • compute.instances.list: to list the compute instances by using the gcloud compute instances list command.

   You can grant these permissions by using either predefined or custom IAM roles. To view information about predefined roles and the permissions that they provide, see IAM roles and permissions index. For information about how to create custom IAM roles, see Create and manage custom roles.

3. Make note of the email address of the service account you created. You need this in a later part of this guide.

Deploy resources for SAP HANA

To deploy the Google Cloud resources for running SAP HANA, such as compute instances, you use the Terraform configuration provided by Google Cloud.

The following instructions use the Cloud Shell, but are generally applicable to the gcloud CLI.

To deploy the resources needed to run the SAP HANA scale-out system, complete the following steps:

1. Verify that your current quotas for resources such as Compute Engine instances, Hyperdisk volumes, Persistent Disk volumes, and CPUs are sufficient for the SAP HANA systems that you are about to deploy. If your quotas are insufficient, then your deployment fails.

   For information about quota requirements to run SAP HANA, see Pricing and quota considerations for SAP HANA.

   Go to Quotas & system limits

2. Open Cloud Shell, or the local terminal where you've installed the gcloud CLI and the Terraform CLI.

3. Go to your working directory.

4. Verify that your working directory doesn't contain any other Terraform configuration file. If it does, then create a new working directory.

5. Download the sap_hana_scaleout.tf configuration file to your working directory:

   wget https://storage.googleapis.com/cloudsapdeploy/terraform/latest/terraform/sap_hana_scaleout/terraform/sap_hana_scaleout.tf
   

6. Open the sap_hana_scaleout.tf file in an editor.

   If you're using Cloud Shell, then you can use its code editor. To launch the editor, click Open Editor on the toolbar of the Cloud Shell window.

7. In the sap_hana_scaleout.tf file, update values for the following arguments. For example, you might update the value **ZONE** with us-central1-f.

   To view an example of a completed configuration file, see Example configuration.

   Argument	Data type	Description
   source	String	Specifies the location and version of the Terraform module to use during deployment. The sap_hana_scaleout.tf configuration file includes two instances of the source argument: one that is active and one that is included as a comment. The source argument that is active by default specifies latest as the module version. The second instance of the source argument, which by default is deactivated by a leading # character, specifies a timestamp that identifies a module version. If you need all of your deployments to use the same module version, then remove the leading # character from the source argument that specifies the version timestamp and add it to the source argument that specifies latest.
   project_id	String	Specify the ID of your Google Cloud project in which you are deploying this system. For example, my-project-x.
   zone	String	Specify the zone in which you are deploying your SAP system. The zone must be in the same region that you selected for your subnet. For example, if your subnet is deployed in the us-central1 region, then you can specify a zone such as us-central1-a.
   machine_type	String	Specify the type of Compute Engine virtual machine (VM) on which you need to run your SAP system. If you need a custom VM type, then specify a predefined VM type with a number of vCPUs that is closest to the number you need while still being larger. After deployment is complete, modify the number of vCPUs and the amount of memory. For example, n1-highmem-32.
   subnetwork	String	Specify the name of the subnetwork that you created in a previous step. If you are deploying to a shared VPC, then specify this value as SHARED_VPC_PROJECT_ID/SUBNETWORK. For example, myproject/network1.
   linux_image	String	Specify the name of the Linux operating system image on which you want to deploy your SAP system. For example, sles-15-sp6-sap. For the list of available operating system images, see the Images page in the Google Cloud console.
   linux_image_project	String	Specify the Google Cloud project that contains the image that you have specified for the argument linux_image. This project might be your own project or a Google Cloud image project. For a Compute Engine image, specify suse-sap-cloud. To find the image project for your operating system, see Operating system details.
   instance_name	String	Specify a name for the host VM instance. The name can contain lowercase letters, numbers, and hyphens. The VM instances for the worker and standby hosts use the same name with a w and the host number appended to the name.
   sap_hana_shared_nfs	String	Specify the NFS mount point for the /hana/shared volume. For example, 10.151.91.122:/hana_shared_nfs.
   sap_hana_backup_nfs	String	Specify the NFS mount point for the /hanabackup volume. For example, 10.216.41.122:/hana_backup_nfs.
   sap_hana_sid	String	To automatically install SAP HANA on the deployed VMs, specify the SAP HANA system ID. The ID must consist of three alpha-numeric characters and begin with a letter. All letters must be in uppercase. For example, HS4.
   sap_hana_instance_number	Integer	Optional. Specify the instance number, 0 to 99, of the SAP HANA system. The default is 0.
   sap_hana_sidadm_uid	Integer	Optional. Specify a value to override the default value of the SID_LCadm user ID. The default value is 900. You can change this to a different value for consistency within your SAP landscape.
   sap_hana_sapsys_gid	Integer	Optional. Overrides the default group ID for sapsys. The default value is 79.
   sap_hana_worker_nodes	Integer	Specify the number of additional SAP HANA worker hosts that you need. You can specify 1 to 15 worker hosts. The default value is 1.
   sap_hana_standby_nodes	Integer	Specify the number of additional SAP HANA standby hosts that you need. You can specify 1 to 3 standby hosts. The default value is 1.
   deploy_infra_only	Boolean	Set the value true to deploy the Google Cloud resources and skip installation of SAP HANA on the deployed compute instances. The default value of this argument is false. When you're using the sap_hana_scaleout.tf configuration provided by Google Cloud, the deployed resources include the following: Compute Engine instances to host the SAP HANA master, worker, and standby nodes. Hyperdisk or Persistent Disk volumes to host the SAP HANA directories, such as /hana/data and /hana/log. This argument is available in sap_hana_scaleout module version 1.9.947102001 or later.
   disk_type	String	Optional. Specify the default type of Persistent Disk or Hyperdisk volume that you want to deploy for the /hana/data, /hana/log, and /usr/sap directories in your deployment. For information about the default disk deployment performed by the Terraform configurations provided by Google Cloud, see Disk deployment by Terraform. The following are valid values for this argument: hyperdisk-extreme, hyperdisk-balanced, pd-ssd, pd-balanced, and pd-extreme. You can override this default disk type and the associated default disk size and default IOPS using some advanced arguments. For more information, navigate to your working directory, then run the terraform init command, and then see the /.terraform/modules/sap_hana_scaleout/variables.tf file. Before you use these arguments in production, make sure to test them in a non-production environment. If you want to use SAP HANA Native Storage Extension (NSE), then you need to provision larger disks by using the advanced arguments.
   use_single_shared_data_log_disk	Boolean	Optional. The default value is false, which directs Terraform to deploy a separate persistent disk or Hyperdisk for each of the following SAP volumes: /hana/data, /hana/log, /hana/shared, and /usr/sap. To mount these SAP volumes on the same persistent disk or Hyperdisk, specify true.
   sap_hana_double_volume_size	Boolean	Optional. To double the HANA volume size, specify true. This argument is useful when you want to deploy multiple SAP HANA instances or a disaster-recovery SAP HANA instance on the same VM. By default, the volume size is automatically calculated to be the minimum size required for the size of your VM, while still meeting the SAP certification and support requirements. The default value is false.
   network_tags	String	Optional. Specify one or more comma-separated network tags that you want to associate with your VM instances for firewall or routing purposes. If you specify public_ip = false and don't specify a network tag, then make sure to provide another means of access to the internet.
   service_account	String	Optional. Specify the email address of a user-managed service account to be used by the host VMs and by the programs that run on the host VMs. For example, svc-acct-name@project-id.iam.gserviceaccount.com. If you specify this argument without a value, or omit it, then the installation script uses the Compute Engine default service account. For more information, see Identity and access management for SAP programs on Google Cloud.
   public_ip	Boolean	Optional. Determines whether or not a public IP address is added to your VM instance. The default value is true.
   sap_deployment_debug	Boolean	Optional. Only when Cloud Customer Care asks you to enable debugging for your deployment, specify true, which makes the deployment generate verbose deployment logs. The default value is false.
   reservation_name	String	Optional. To use a specific Compute Engine VM reservation for this deployment, specify the name of the reservation. By default, the installation script selects any available Compute Engine reservation based on the following conditions. For a reservation to be usable, regardless of whether you specify a name or the installation script selects it automatically, the reservation must be set with the following: The specificReservationRequired option is set to true or, in the Google Cloud console, the Select specific reservation option is selected. Some Compute Engine machine types support CPU platforms that are not covered by the SAP certification of the machine type. If the target reservation is for any of the following machine types, then the reservation must specify the minimum CPU platforms as indicated: n1-highmem-32: Intel Broadwell n1-highmem-64: Intel Broadwell n1-highmem-96: Intel Skylake m1-megamem-96: Intel Skylake The minimum CPU platforms for all of the other machine types that are certified by SAP for use on Google Cloud conform to the SAP minimum CPU requirement.
   vm_static_ip	String	Optional. Specify a valid static IP address for the VM instance. If you don't specify one, then an IP address is automatically generated for your VM instance. This argument is available in sap_hana_scaleout module version 202306120959 or later.
   worker_static_ips	List(String)	Optional. Specify an array of valid static IP addresses for the worker instances in your scale-out system. If you don't specify a value for this argument, then an IP address is automatically generated for each worker VM instance. For example, [ "1.0.0.1", "2.3.3.4" ]. The static IP addresses are assigned in the order of instance creation. For example, if you choose to deploy 3 worker instances but specify only 2 IP addresses for the argument worker_static_ips, then these IP addresses are assigned to the first two VM instances that the Terraform configuration deploys. For the third worker VM instance, the IP address is automatically generated. This argument is available in sap_hana_scaleout module version 202306120959 or later.
   standby_static_ips	List(String)	Optional. Specify an array of valid static IP addresses for the standby instances in your scale-out system. If you don't specify a value for this argument, then an IP address is automatically generated for each standby VM instance. For example, [ "1.0.0.1", "2.3.3.4" ]. The static IP addresses are assigned in the order of instance creation. For example, if you choose to deploy 3 standby instances but specify only 2 IP addresses for the argument standby_static_ips, then these IP addresses are assigned to the first two VM instances that the Terraform configuration deploys. For the third standby VM instance, the IP address is automatically generated. This argument is available in sap_hana_scaleout module version 202306120959 or later.

8. Initialize your current working directory and download the Terraform provider plugin and module files for Google Cloud:

   terraform init
   

   The terraform init command prepares your working directory for other Terraform commands.

   To force a refresh of the provider plugin and configuration files in your working directory, specify the --upgrade flag. If the --upgrade flag is omitted and you don't make any changes in your working directory, Terraform uses the locally cached copies, even if latest is specified in the source URL.

9. Optionally, create the Terraform execution plan:

   terraform plan
   

   The terraform plan command shows the changes required by your current configuration. If you skip this step, then the terraform apply command automatically creates a new plan and prompts you to approve it.

10. Apply the execution plan:

    terraform apply
    

    When you are prompted to approve the actions, enter yes.

    The terraform apply command sets up the Google Cloud infrastructure. When the Compute Engine machine boots, the Google Cloud infrastructure invokes startup scripts that configure the operating system and install SAP HANA.

    While Terraform has control, status messages are written to the Cloud Shell. After the scripts are invoked, status messages are written to Logging and are viewable in the Google Cloud console, as described in Check the Logging logs.

    Time to completion can vary, but the entire process usually takes 20-30 minutes.

Example configuration

The following example shows a completed configuration file that deploys resources for an SAP HANA scale-out system with three worker hosts and one standby host in the us-central1-f zone. Each host is installed on an n2-highmem-32 instance that runs on SLES for SAP 15 SP6 operating system provided by a Compute Engine public image. The NFS volumes are provided by Filestore.

For clarity, comments in the configuration file are omitted in the example.

# ...
module "hana_scaleout" {
source = "https://storage.googleapis.com/cloudsapdeploy/terraform/latest/terraform/sap_hana_scaleout/sap_hana_scaleout_module.zip"
#
# By default, this source file uses the latest release of the terraform module
# for SAP on Google Cloud. To fix your deployments to a specific release
# of the module, comment out the source property above and uncomment the source property below.
#
# source = "https://storage.googleapis.com/cloudsapdeploy/terraform/latest/terraform/sap_hana_scaleout/sap_hana_scaleout_module.zip"
#
# ...
#
project_id = "example-project-123456"
zone = "us-central1-f"
machine_type = "n1-highmem-32"
subnetwork = "example-sub-network-sap"
linux_image = "sles-15-sp6-sap"
linux_image_project = "suse-sap-cloud"

instance_name = "hana-scaleout-w-failover"
sap_hana_sid = "HS4"
sap_hana_shared_nfs = "10.74.146.58:/hana_shr"
sap_hana_backup_nfs = "10.188.249.170:/hana_bup"
# ...
sap_hana_instance_number = 11
# ...
sap_hana_worker_nodes = 3
sap_hana_standby_nodes = 1
vm_static_ip = "10.0.0.1"
worker_static_ips = ["10.0.0.2", "10.0.0.3", "10.0.0.4"]
standby_static_ips = ["10.0.0.5"]
deploy_infra_only  = true
# ...
}

Create VPC firewall rules to verify deployment

To verify your deployment, create the following firewall rules:

• A firewall rule that allows SSH connections on port 22 of each of the deployed compute instances from your local workstation, a bastion host, or a jump server.
• A firewall rule that allows all connection types on any port of any of the deployed compute instances.

For information about how to create firewall rules, see Create VPC firewall rules.

Verify the deployment of resources

To verify that your Terraform configuration file has successfully deployed the Google Cloud resources required for your SAP HANA scale-out system, you must perform the following:

• Check the logs
• Check the disks attached to the compute instances
• Check the configured filesystems
• If needed, clean up and retry deployment

Check the logs

1. In the Google Cloud console, open Cloud Logging to monitor installation progress and check for errors.

   Go to Cloud Logging

2. Filter the logs:

   1. In the Logs Explorer page, go to the Query pane.

   2. From the Resource drop-down menu, select Global, and then click Add.

      If you don't see the Global option, then in the query editor, enter the following query:

      resource.type="global"
      "Deployment"
      

   3. Click Run query.

3. Analyze the filtered logs:

   • If "--- Finished" is displayed, then the deployment processing is complete and you can proceed to the next step.

   • If you see a quota error:

     1. On the IAM & Admin Quotas page, increase any of your quotas that do not meet the SAP HANA requirements that are listed in the SAP HANA planning guide.

     2. Open Cloud Shell.

        Go to Cloud Shell

     3. Go to your working directory and delete the deployment to clean up the VMs and persistent disks from the failed installation:

        terraform destroy

        When you are prompted to approve the action, enter yes.

     4. Rerun your deployment.

Check the disks attached to the compute instances

After the deployment is complete, check the disks attached to the deployed compute instances. The disk names indicate their role in the SAP HANA scale-out system.

To check the disks attached to the compute instances, complete the following steps:

1. In the Google Cloud console, go to the Compute Engine Disks page.

   Go to Disks

2. View the values in the Name and In use by fields.

   The value in the In use by field is the name of the compute instance to which the disk is attached. The disk that has data00001 in its name is deployed to host the /hana/data directory of the master node. Similarly, the disk that has log00002 in its name is deployed to host the /hana/log directory of a worker node. Notice that the compute instance that hosts the standby node has only one disk attached in addition to the boot disk, which is to host the /usr/sap directory.

Alternatively, you can go to the VM instances page, click the deployed compute instances, and view disk details.

Check the configured filesystems

Check the filesystems configured on the master node, a worker node, and a standby node as follows:

1. In the Google Cloud console, go to the Compute Engine VM instances page.

   Go to VM instances

2. Click the SSH button available against the compute instance deployed to run the SAP HANA master node.

   You can identify this compute instance by viewing its name; it doesn't contain any suffix, unlike the worker and standby nodes.

3. In the terminal of the compute instance, switch to the root user:

   sudo su -
   

4. Display information about configured filesystems:

   df -h -x tmpfs
   

   Your output is similar to the following example. Notice that the logical volumes and volume groups are yet to be created. These actions are performed later in this guide.

   hana-scaleout-w-failover:~ # df -h -x tmpfs
   Filesystem                         Size  Used Avail Use% Mounted on
   /dev/sda3                           45G  7.7G   38G  18% /
   devtmpfs                           4.0M  8.0K  4.0M   1% /dev
   efivarfs                           256K   26K  226K  11% /sys/firmware/efi/efivars
   /dev/sda2                           20M  3.9M   17M  20% /boot/efi

5. Repeat the preceding set of steps for a worker node and a standby node.

   Similar to the master node, the /hana/data and /hana/log directories are not mounted on the worker and standby nodes.

   On a worker node, your output is similar to the following example:

   hana-scaleout-w-failoverw1:~ # df -h -x tmpfs
   Filesystem                         Size  Used Avail Use% Mounted on
   /dev/sda3                           45G  7.6G   38G  17% /
   devtmpfs                           4.0M  8.0K  4.0M   1% /dev
   efivarfs                           256K   27K  225K  11% /sys/firmware/efi/efivars
   /dev/sda2                           20M  3.9M   17M  20% /boot/efi

   On a standby node, your output is similar to the following example:

   hana-scaleout-w-failoverw4:~ # df -h -x tmpfs
   Filesystem                         Size  Used Avail Use% Mounted on
   /dev/sda3                           45G  7.6G   38G  17% /
   devtmpfs                           4.0M  8.0K  4.0M   1% /dev
   efivarfs                           256K   27K  225K  11% /sys/firmware/efi/efivars
   /dev/sda2                           20M  3.9M   17M  20% /boot/efi

Clean up and retry deployment

If any of the deployment verification steps in the preceding sections show that the installation wasn't successful, then you must undo your deployment and retry it by completing the following steps:

1. Resolve any errors to ensure that your deployment doesn't fail again for the same reason. For information about checking the logs, or resolving quota related errors, see Check the logs.

2. Open Cloud Shell or, if you installed the Google Cloud CLI on your local workstation, then open a terminal.

   Open Cloud Shell

3. Go to the directory that contains the Terraform configuration file that you used for this deployment.

4. Delete all resources that are part of your deployment by running the following command:

   terraform destroy

   When you are prompted to approve the action, enter yes.

5. Retry your deployment as instructed earlier in this guide.

Optimize OS configuration

Optimizing the Linux kernel network and memory management subsystems is critical for system performance and ensuring that the environment meets SAP support requirements. You must also ensure that the necessary OS packages are installed.

To optimize the OS configuration for your SAP HANA scale-out system, perform the following on all the underlying compute instances:

• Tune the kernel and network settings
• Install OS packages
• Set up passwordless SSH access for all nodes

Tune the kernel and network settings

1. In the Google Cloud console, go to the Compute Engine VM instances page.

   Go to VM instances

2. Click the SSH button available against the compute instance deployed to run the SAP HANA master node.

3. Ensure that SELINUX is disabled by completing the following steps:

   1. Edit the /etc/selinux/config file and set SELINUX=disabled:

      sudo sed -i 's/^SELINUX=.*/SELINUX=disabled/g' /etc/selinux/config
      

   2. Apply the change:

      sudo setenforce 0
      

4. In the /etc/default/grub file, verify that the following boot parameter values are set:

   transparent_hugepage=never
   intel_idle.max_cstate=1
   processor.max_cstate=1
   intel_iommu=off

   You can run the following command to view these parameter values:

   grep -E "transparent_hugepage|intel_idle.max_cstate|processor.max_cstate|intel_iommu" /etc/default/grub
   

   If the parameter values are different, then update them by completing the following steps:

   1. Edit the /etc/default/grub file:

       vi /etc/default/grub
       ```
      

   2. Append the following to the file's contents:

       GRUB_CMDLINE_LINUX_DEFAULT="transparent_hugepage=never intel_idle.max_cstate=1 processor.max_cstate=1 intel_iommu=off
       ```
      

   3. Regenerate the /etc/default/grub file:

       grub2-mkconfig -o /boot/grub2/grub.cfg
       ```
      

   4. Verify that the boot parameter values are set correctly:

       grep -E "transparent_hugepage|intel_idle.max_cstate|processor.max_cstate|intel_iommu" /etc/default/grub
       ```
      

5. To help ensure the optimal performance and stability of the SAP HANA scale-out system, tune the kernel and network parameters by completing the following steps:

   1. Edit the /etc/sysctl.conf file:

      vi /etc/sysctl.conf
      

   2. Append the following parameter values to the file's contents:

      net.ipv4.tcp_slow_start_after_idle=0
      kernel.numa_balancing = 0
      net.core.somaxconn = 4096
      net.ipv4.tcp_tw_reuse = 1
      net.ipv4.tcp_timestamps = 1
      net.ipv4.tcp_syn_retries = 8
      net.ipv4.tcp_wmem = 4096 16384 4194304
      

6. If your compute instance uses the VirtIO network interface card, then you must optimize it.

   • To check if your compute instance uses VirtIO:

     lsmod | grep -q virtio_net
     

   • If your compute instance uses VirtIO, then append the following parameter value to the /etc/sysctl.conf file:

     net.ipv4.tcp_limit_output_bytes = 1048576
     

7. To force the OS to apply all updated parameter values instantly, without requiring the compute instance to reboot, run the following command:

   sysctl -p
   

8. Repeat steps 3-7 for all the worker and standby nodes in your SAP HANA scale-out system.

Install OS packages

1. Prepare the OS by ensuring that it includes the software components specified in the following SAP notes:

   • 2578899 - SUSE Linux Enterprise Server 15: Installation Note
   • 1984787 - SUSE LINUX Enterprise Server 12: Installation notes

2. Activate the SAP tuning profile by applying the standard SAP HANA solution profile and enabling the background daemon to maintain these configuration parameters across reboots:

   saptune solution apply HANA
   saptune service takeover
   systemctl enable saptune
   

3. Install Google Cloud's Agent for SAP.

   Google Cloud's Agent for SAP is required for SAP support of SAP systems running on Google Cloud, including SAP NetWeaver, SAP HANA, SAP ASE, SAP MaxDB, and others. To install the agent, follow the instructions described in the guide of your choice:

   • To install the agent individually on all the deployed compute instances by using a package manager, see Install and configure Google Cloud's Agent for SAP on a Compute Engine instance.

   • To install and manage the agent on a fleet of VMs by using VM Extension Manager, see Install and manage Agent for SAP on a fleet of VMs.

Set up passwordless SSH access for all nodes

An SAP HANA scale-out system that uses the host auto-failover solution requires seamless, passwordless communication between all nodes using the root user. For passwordless SSH access, you need to add the SSH public keys to the instance metadata of all deployed instances. The format of the metadata is USERNAME: PUBLIC-KEY-VALUE.

For information about adding SSH keys to compute instances, see Add SSH keys to VMs that use metadata-based SSH keys.

Configure storage for the scale-out system

To configure storage for the SAP HANA scale-out system, you must complete the following tasks:

• Configure swap space
• Set up NFS storage

Configure swap space

• On all the nodes that you've created for your SAP HANA scale-out system, you must configure the swap file or dedicated swap partition.

  For information about SWAP space recommendations for SAP HANA, see the SAP note 1999997 - FAQ: SAP HANA memory.

Set up NFS storage

An SAP HANA scale-out system requires an NFS solution, such as Filestore, to share the /hana/shared and /hanabackup directories between all nodes.

To set up NFS storage for the /hana/shared and /hanabackup directories, complete the following steps:

1. Verify that you've set up the NFS solution.

2. Verify that the NFS volumes that you've created are empty.

   Any existing files can conflict with the deployment process, particularly if the files or folder reference the SAP system ID (SID) that you've assigned for your SAP HANA scale-out system. The deployment process cannot determine whether the files can be overwritten.

3. Install and configure the autofs package to mount the /hana/shared and /hanabackup NFS volumes on the compute instance when the file directories are first accessed.

   To configure the autofs package, complete the following steps:

   1. Establish an SSH connection with the compute instance that you've deployed for the SAP HANA master node.

   2. Install the autofs package. This package ensures that the core automounter daemon is present on the system.

      zypper in -y autofs
      

   3. Append the direct map definition to the master configuration:

      echo "/- /etc/auto.hana" | sudo tee -a /etc/auto.master
      

   4. Define the production-optimized performance mount options:

      NFS_OPTS="-rsize=1048576,vers=3,mountvers=3,wsize=1048576,hard,intr,timeo=18,retrans=200"
      

   5. Create and populate the sub-map file with your NFS solution paths:

      echo "/hana/shared ${NFS_OPTS} HANA_SHARED_NFS_IP:/HANA_SHARED_NFS_EXPORT_PATH" | sudo tee -a /etc/auto.hana
      echo "/hanabackup ${NFS_OPTS} HANA_BACKUP_NFS_IP:/HANA_BACKUP_NFS_EXPORT_PATH" | sudo tee -a /etc/auto.hana
      

      Replace the following:

      • HANA_SHARED_NFS_IP: the IP address of the NFS solution that you've created to host the /hana/shared directory
      • HANA_SHARED_NFS_EXPORT_PATH: the name of the file share that you've provisioned in the NFS solution, to host the /hana/shared directory
      • HANA_BACKUP_NFS_IP: the IP address of the NFS solution that you've created to host the /hanabackup directory
      • HANA_BACKUP_NFS_EXPORT_PATH: the name of the file share that you've provisioned in the NFS solution, to host the /hana/backup directory

   6. Refresh the system mount engine:

      sudo systemctl daemon-reload
      

   7. Enable and start the autofs service:

      sudo systemctl enable --now autofs
      

   8. Access each directory to trigger autofs and thereby mount the NFS volumes. For example:

      cd /hana/shared
      cd /hanabackup
      

   9. Verify that the directories have been mounted:

      df -Th | grep FILE_SHARE_NAME
      

      Replace FILE_SHARE_NAME with the name of the file share that you've created in your NFS solution. The output is similar to the following example:

      10.52.158.66:/nfs_hana_shared              nfs       1.0T   37G  988G   4% /hana/shared
      10.52.158.2:/nfs_hana_bkp                  nfs       1.0T     0  1.0T   0% /hanabackup

   10. Configure the autofs package on all the compute instances that you've deployed to run the worker and standby. You do this by repeating steps a-h in this procedure.

Set up disks and LVM configuration for storage manager for SAP HANA

In an SAP HANA scale-out system that uses the host auto-failover solution, the /usr/sap directory remains permanently mounted locally on each host. However, the production performance paths for the /hana/data and /hana/log directory must be managed dynamically.

The Google Cloud storage manager for SAP HANA standby nodes (gceStorageClient) requires that the volume groups (VG) and logical volumes (LV) for the /hana/data and /hana/log directories are initially formatted and initialized under strict ownership constraints, and then immediately unmounted and deactivated. This offline state is mandatory because it allows the gceStorageClient API scripts to safely attach, activate, and mount the block volumes over the Google Cloud infrastructure layer to whichever active node is assigned the partition identity during database initialization or host failover events.

The following steps create a permanent mount for your SAP HANA binaries (/usr/sap) while preparing the /hana/data and /hana/log directories for dynamic cloud orchestration by using the storage manager for SAP HANA.

To set up the disks and LVM configuration, complete the following steps:

1. On the master node of your scale-out system, complete the following steps:

   1. Identify the disk device names for the Google Cloud storage volumes:

      sudo ls -l /dev/disk/by-id/google-*
      

      The output is a symlink mapping, which looks like the following example:

      ~ # ls -l /dev/disk/by-id/google-*
      lrwxrwxrwx 1 root root  9 Jun  5 20:53 /dev/disk/by-id/google-hana-scaleout-w-failover-usrsap00001 -> ../../sdd
      lrwxrwxrwx 1 root root  9 Jun  5 20:53 /dev/disk/by-id/google-hana-scaleout-w-failover-data00001 -> ../../sde
      lrwxrwxrwx 1 root root  9 Jun  5 20:53 /dev/disk/by-id/google-hana-scaleout-w-failover-log00001 -> ../../sdf

   2. Make note of the disk device names that correspond to the /hana/data, /hana/log, and /usr/sap names. You use these in the next step.

   3. Define environment variables for the disk paths:

      DISK_USRSAP="/dev/disk/by-id/google-USR_SAP_DISK_NAME"
      DISK_DATA="/dev/disk/by-id/google-HANA_DATA_DISK_NAME"
      DISK_LOG="/dev/disk/by-id/google-HANA_LOG_DISK_NAME"
      SAPHANA_SID="SID"
      

      Replace the following:

      • USR_SAP_DISK_NAME: the name of the disk that you've created for the /usr/sap directory on the master node
      • HANA_DATA_DISK_NAME: the name of the disk that you've created for the /hana/data directory on the master node
      • HANA_LOG_DISK_NAME: the name of the disk that you've created for the /hana/log directory on the master node
      • SID: the SAP system ID (SID) of the SAP HANA scale-out system

   4. Format and mount the /hana/data and /hana/log directories:

      1. Create and format the logical volume for /hana/data:

         sudo pvcreate ${DISK_DATA}
         sudo vgcreate vg_hana_data ${DISK_DATA}
         sudo lvcreate -l 100%FREE -n data vg_hana_data
         sudo mkfs.xfs /dev/vg_hana_data/data
         

      2. Create and format the logical volume for /hana/log:

         sudo pvcreate ${DISK_LOG}
         sudo vgcreate vg_hana_log ${DISK_LOG}
         sudo lvcreate -l 100%FREE -n log vg_hana_log
         sudo mkfs.xfs /dev/vg_hana_log/log
         

      3. Mount the logical volumes and update their ownership:

         sudo mkdir -p /hana/data /hana/log
         sudo mount -t xfs -o logbsize=256k /dev/vg_hana_data/data /hana/data
         sudo mount -t xfs -o logbsize=256k /dev/vg_hana_log/log /hana/log
         sudo chown -R 900:79 /hana/data /hana/log
         sudo chmod -R 755 /hana/data /hana/log
         

   5. Format and mount the /usr/sap directory:

      1. Initialize the raw disk as an LVM Physical Volume (PV):

         sudo pvcreate ${DISK_USRSAP}
         

      2. Combine the PV into a dedicated Volume Group (VG) for /usr/sap:

         sudo vgcreate vg_hana_usrsap ${DISK_USRSAP}
         

      3. Allocate 100% of the space to a Logical Volume (LV) named usrsap:

         sudo lvcreate -l 100%FREE -n usrsap vg_hana_usrsap
         

      4. Format the volume using XFS file system:

         sudo mkfs.xfs /dev/vg_hana_usrsap/usrsap
         

      5. Create the local anchor directory if it does not exist:

         sudo mkdir -p /usr/sap
         

      6. Append a permanent entry to the system file table (/etc/fstab):

         echo "/dev/vg_hana_usrsap/usrsap /usr/sap xfs defaults,nofail,logbsize=256k 0 2" | sudo tee -a /etc/fstab
         

      7. Refresh the system mount engine and mount the disk immediately:

         sudo systemctl daemon-reload && sudo mount -a
         

   6. Unmount and deactivate the logical volumes so that the storage manager for SAP HANA can control them:

      1. Flush all pending data from system cache blocks to physical disk:

         sudo sync
         

      2. Unmount the data and log directories:

         sudo umount /hana/log
         sudo umount /hana/data
         

      3. Deactivate the volume groups so they are offline:

         sudo vgchange -a n vg_hana_data
         sudo vgchange -a n vg_hana_log
         

   7. Recreate empty mount points for successful installation of SAP HANA.

      Because the logical volumes for /hana/data and /hana/log were unmounted in the previous step, the physical paths /hana/data/SID and /hana/log/SID vanished from your root partition view. You must recreate the physical paths as empty baseline folders to avoid issues during SAP HANA installation.

      sudo mkdir -p /hana/data/${SAPHANA_SID} /hana/log/${SAPHANA_SID}
      

2. Format and mount the /hana/data, /hana/log, and /usr/sap directories on all the worker nodes of your scale-out system by repeating the previous step for all of them.

3. On all the standby nodes of your scale-out system, initialize and mount the /usr/sap disk:

   1. Identify the disk device names for the Google Cloud storage volumes:

      sudo ls -l /dev/disk/by-id/google-*
      

      The output is a symlink mapping, which looks like the following example:

      ~ # ls -l /dev/disk/by-id/google-*
      lrwxrwxrwx 1 root root  9 Jun  5 20:53 /dev/disk/by-id/google-hana-scaleout-w-failoverw4-usrsap00001 -> ../../sdd

   2. Make note of the disk device name used by the /usr/sap directory. You use this in the next step.

   3. Define environment variable for the disk path:

      DISK_USRSAP="/dev/disk/by-id/google-USR_SAP_DISK_NAME_ON_STANDBY_NODE"
      SAPHANA_SID="SID"
      

      Replace USR_SAP_DISK_NAME_ON_STANDBY_NODE with the name of the disk that noted in the previous step.

   4. Format and mount the /usr/sap directory:

      sudo pvcreate /dev/disk/by-id/google-USR_SAP_DISK_NAME_ON_STANDBY_NODE
      sudo vgcreate vg_hana_usrsap /dev/disk/by-id/google-USR_SAP_DISK_NAME_ON_STANDBY_NODE
      sudo lvcreate -l 100%FREE -n usrsap vg_hana_usrsap
      sudo mkfs.xfs /dev/vg_hana_usrsap/usrsap
      sudo mkdir -p /usr/sap
      echo "/dev/vg_hana_usrsap/usrsap /usr/sap xfs defaults,nofail,logbsize=256k 0 2" | sudo tee -a /etc/fstab
      sudo systemctl daemon-reload && sudo mount -a
      

   5. Recreate empty mount points for successful installation of SAP HANA.

      Because the logical volumes for /hana/data and /hana/log were unmounted the previous step, the physical paths /hana/data/SID and /hana/log/SID vanished from your root partition view. You must recreate the physical paths as empty baseline folders to avoid issues during SAP HANA installation.

      sudo mkdir -p /hana/data/${SAPHANA_SID} /hana/log/${SAPHANA_SID}
      

Install and configure storage manager for SAP HANA

The Google Cloud storage manager for SAP HANA (gceStorageClient) is a high-availability framework that you can use to handle dynamic disk attachment, disk detachment, fencing, and file system mounts during a host failover event.

When a takeover occurs, the host auto-failover solution uses the SAP HANA Storage Manager API and the Google Cloud storage manager for SAP HANA standby nodes to move the volume mounts from the failed host to the standby host.

On Google Cloud, the storage manager for SAP HANA is required for SAP HANA systems that use the SAP HANA host auto-failover solution. To deploy it successfully, you must install the OS level binaries across all hosts, delegate specific root-level execution privileges to the SID_LCadm user, and define the master topology mapping inside the global.ini under /hana/shared.

Install the storage manager

You must install the storage manager for SAP HANA on all the nodes of your scale-out system as follows:

1. Establish an SSH connection with a compute instance that you've deployed.

2. Update mandatory Python dependency modules:

   sudo zypper in -f -y python3-pyasn1-modules
   

3. Register the official Google Cloud gceStorageClient repository:

   sudo zypper addrepo --gpgcheck-allow-unsigned-package --refresh https://packages.cloud.google.com/yum/repos/google-sapgcestorageclient-sles$(grep -oP '(?<=^VERSION_ID=).+' /etc/os-release | tr -d '"' | cut -f1 -d.)-\$basearch google-sapgcestorageclient
   

4. Install the gceStorageClient package:

   sudo zypper --no-gpg-checks install -y google-sapgcestorageclient
   

5. Repeat the steps described in this section on all the other compute instances you've deployed to run your scale-out system.

Configure the file system

To provision environment configurations in the /hana/shared file system, you must run the script provided by Google Cloud:

1. Establish an SSH connection to the compute instance that you've deployed to run the SAP HANA master node.

2. Configure the file system by running the provided script:

   sudo /usr/sap/google-sapgcestorageclient/install.sh
   sudo chmod +x /hana/shared/gceStorageClient/send_metrics.sh
   

   Although you've run this script from the master node, the changes are instantly propagated to all the nodes of your scale-out system. This is because the /hana/shared directory is accessible from all the nodes.

Configure OS for the storage manager

To help the SAP HANA databases worker tasks to securely interact with the underlying infrastructure, you must configure the OS for the gceStorageClient on all the nodes of your scale-out system. To do this, complete the following steps:

1. Establish an SSH connection with a compute instance that you've deployed.

2. Configure the gcloud CLI to work under the target SAP HANA SID_LCadm user account:

   mkdir -p /usr/sap/SID/home/.config/gcloud/
   chown -R 900:79 /usr/sap/SID/home/.config/gcloud/
   

3. Enable the gceStorageClient tool to run low-level Linux administration actions, such as managing the volume groups and flushing the CSCI mappings. You do this by adding the necessary paths to an allowlist in the system sudoers registry as follows:

   1. Safely create a new sudo permission files by using visudo:

      sudo visudo -f /etc/sudoers.d/gceStorageClient
      

   2. Append the following block to this file:

      SID_LCadm ALL=NOPASSWD: /sbin/multipath,/sbin/multipathd,/usr/bin/sg_persist,/bin/mount,/bin/umount,/bin/kill,/usr/bin/lsof,/usr/bin/systemctl,/sbin/xfs_repair,/usr/bin/mkdir,/sbin/vgscan,/sbin/pvscan,/sbin/lvscan,/sbin/vgchange,/sbin/lvdisplay,/usr/bin/gcloud,/sbin/dmsetup
      

   3. Make sure that the /etc/sudoers file includes the following:

      • For SLES for SAP 15 SP3 or later:

        @includedir /etc/sudoers.d
        

      • For versions up to SLES for SAP 15 SP2:

        #includedir /etc/sudoers.d
        

        The # in this text is part of the syntax and does not mean that the line is a comment.

4. Repeat the steps described in this section on all the other compute instances you've deployed to run your scale-out system.

Configure the storage manager

You must configure the Google Cloud storage manager for SAP HANA to link the disks you've deployed with their respective SAP HANA scale-out partition ID values. You do this by using the information available in the global.ini file of the SAP Storage Connector.

To configure storage manager for SAP HANA, complete the following steps:

1. Establish an SSH connection with the compute instance that you've deployed to run the SAP HANA master node.

2. Navigate to the hana/shared/gceStorageClient directory and edit the global.ini file:

   cd /hana/shared/gceStorageClient
   vi global.ini
   

3. Include the disk-to-partition ID mapping by using the following format:

   partition_PARTITION_NUMBER_USAGE_TYPE__PARAMETER= VALUE
   

   Replace the following:

   • PARTITION_NUMBER: the partition number, which can be a number or the wildcard *.
   • USAGE_TYPE: the usage type of the disk, which can be data, log, or the wildcard *.
   • PARAMETER and VALUE are user-defined values.

   The following is an example of an edited global.ini file:

   [persistence]
   basepath_datavolumes = /hana/data/HS4
   basepath_logvolumes = /hana/log/HS4
   use_mountpoints = yes
   basepath_shared = no
   [storage]
   ha_provider = gceStorageClient
   ha_provider_path = /hana/shared/gceStorageClient
   partition_1_data__pd = hana-scaleout-w-failover-data00001
   partition_1_log__pd = hana-scaleout-w-failover-log00001
   partition_2_data__pd = hana-scaleout-w-failoverw1-data00002
   partition_2_log__pd = hana-scaleout-w-failoverw1-log00002
   partition_3_data__pd = hana-scaleout-w-failoverw2-data00003
   partition_3_log__pd = hana-scaleout-w-failoverw2-log00003
   partition_4_data__pd = hana-scaleout-w-failoverw3-data00004
   partition_4_log__pd = hana-scaleout-w-failoverw3-log00004
   partition_*_data__dev = /dev/vg_hana_data/data
   partition_*_log__dev = /dev/vg_hana_log/log
   partition_*_data__mountOptions = -t xfs -o logbsize=256k
   partition_*_log__mountOptions = -t xfs -o logbsize=256k
   partition_*_*__fencing = disabled
   [trace]
   ha_gcestorageclient = info

   In this example:

   • partition_1_data__pd is the name of the disk that hosts the /hana/data directory on the first node of your SAP HANA system, which usually is the master node.
   • partition_1_log__pd is the name of the disk that hosts the /hana/log directory on the first node of your SAP HANA system, which usually is the master node.
   • partition_*_data__dev is the path to the logical volume, such as /dev/vg_hana_data/data, inside the compute instance.

4. Include the email address of the service account that you created for the storage manager for SAP HANA:

   partition_*_*__gcloudAccount = STORAGE_CLIENT_SERVICE_ACCOUNT
   

   Replace STORAGE_CLIENT_SERVICE_ACCOUNT with the email address of the service that you created in the Set up a service account for the storage manager for SAP HANA section.

Install and configure SAP HANA

This section uses the SAP HANA database lifecycle manager (HDBLCM) to install SAP HANA on the deployed compute instances.

Because you're using Google Cloud storage manager for SAP HANA (gceStorageClient), you also create a hana_install.cfg configuration file with the following parameter: storage_cfg=/hana/shared/gceStorageClient. This configuration directs HDBLCM to bypass standard storage checks and rely on gceStorageClient to handle the mounting profiles during failover events.

Install and configure the SAP HANA master node

On the compute instance that you've deployed to run the SAP HANA master node, complete the following steps:

1. Establish an SSH connection with the compute instance that you've deployed to run the SAP HANA master node.

   You can identify this compute instance by viewing its name; it doesn't contain any suffix, unlike the worker and standby nodes. For example, in the example described in this guide, the name of the compute instance meant to run the SAP HANA master node is hana-scaleout-w-failover.

2. Create the hana_install.cfg configuration file:

   1. Create the deployment directory

      sudo mkdir -p /root/.deploy
      

   2. Create the silent configuration file hana_install.cfg:

      sudo tee /root/.deploy/hana_install.cfg > /dev/null << 'EOF'
      [General]
      components=client,server
      [Server]
      sid=HS4
      number=00
      userid=900
      groupid=79
      apply_system_size_dependent_parameters=off
      autostart=y
      # Connects the core SAP HANA kernel parameters to the Google Storage Client hooks
      storage_cfg=/hana/shared/gceStorageClient
      EOF
      

3. Download the SAP HANA installation media and extract it in a directory.

4. In directory where you've extracted the SAP HANA installation media, initiate SAP HANA installation by using the HDBLCM tool. The following step also references the hana_install.cfg file that you've created:

   sudo ./hdblcm --configfile=/root/.deploy/hana_install.cfg
   

Add the worker and standby nodes

After you've successfully configured the SAP HANA master node, you must add the worker and standby nodes to your deployment as follows:

1. In the master node, create the add_hosts.cfg configuration file that defines the hostnames and their operational roles in the scale-out deployment as follows.

   • In the [AddHosts] section, add the hostnames and assign them the role of worker or standby.
   • Include the storage_cfg=/hana/shared/gceStorageClient parameter.

   The following is an example configuration:

   sudo tee /root/.deploy/add_hosts.cfg > /dev/null << 'EOF'
   [AddHosts]
   # Register all target worker and standby hosts simultaneously
   addhosts=WORKER1_HOSTNAME:role=worker,WORKER2_HOSTNAME:role=worker,STANDBY1_HOSTNAME:role=standby
   storage_cfg=/hana/shared/gceStorageClient
   listen_interface=global
   root_user=root
   EOF
   

   Replace the following:

   • WORKER1_HOSTNAME: the name of the compute instance that you've deployed to run a worker node in your SAP HANA scale-out system
   • STANDBY1_HOSTNAME: the name of the compute instance that you've deployed to run a standby node in your SAP HANA scale-out system

2. Apply this configuration:

   1. Navigate to the directory where you've installed the HDBLCM tool:

      cd /hana/shared/SID/hdblcm
      

   2. Run the HDBLCM tool with reference to the add_hosts.cfg file that you've created:

      sudo ./hdblcm --action=add_hosts --configfile=/root/.deploy/add_hosts.cfg
      

   3. Follow the prompts on the screen to apply the configuration. This includes entering the storage partition ID for each node that you've defined in the global.ini file.

Verify that autostart is active

1. Establish an SSH connection with the compute instance that runs the SAP HANA master node.

2. Verify that autostart is enabled in the SAP HANA instance profile:

   grep "Autostart" /hana/shared/SID/profile/*
   

   The output must be similar to the following example and include **Autostart=1**:

   hana-scaleout-w-failover:hs4adm> grep "Autostart" /hana/shared/HS4/profile/*
   /hana/shared/HS4/profile/HS4_HDB00_hana-scaleout-w-failover:Autostart=1
   /hana/shared/HS4/profile/HS4_HDB00_hana-scaleout-w-failoverw1:Autostart=1
   /hana/shared/HS4/profile/HS4_HDB00_hana-scaleout-w-failoverw2:Autostart=1
   /hana/shared/HS4/profile/HS4_HDB00_hana-scaleout-w-failoverw3:Autostart=1
   /hana/shared/HS4/profile/HS4_HDB00_hana-scaleout-w-failoverw4:Autostart=1
   hana-scaleout-w-failover:hs4adm>

Enable fencing

1. Establish an SSH connection with the compute instance that runs the SAP HANA master node.

2. To enable fencing in your SAP HANA scale-out system, update the global.ini file by running the following commands.

   The cdcoc command navigates to the /usr/sap/SID/SYS/global/hdb/custom/config directory, which contains the global.ini file.

   sudo su - SID_LCadm
   cdcoc
   sed -i -e 's/partition_\*_\*__fencing = disabled/partition_*_*__fencing = enabled/g' global.ini
   

3. Verify that fencing is enabled by reviewing the updated the global.ini file:

   cat global.ini | grep fencing
   

   The output is similar to the following:

   partition_*_*__fencing = enabled
   

Configure the secondary and tertiary master nodes

Configuring the secondary and tertiary master nodes helps SAP HANA clearly determine which active node in the scale-out system must be promoted as the new master node in case of a failover event.

To configure the secondary and tertiary master nodes, complete the following steps:

1. Establish an SSH connection with the compute instance that runs the SAP HANA master node.

2. Switch to the SID_LCadm user:

   sudo su - SID_LCadm
   

3. Create the update_landscape.sql file and add the names and roles of all the nodes in your SAP HANA scale-out system.

   In the following example, the first worker node and the first standby node are designated as the secondary and tertiary master nodes, respectively.

   cat << 'EOF' > update_landscape.sql
   CALL SYS.UPDATE_LANDSCAPE_CONFIGURATION('deploy','{
     "HOSTS": {
       "WORKER1_HOSTNAME": {
         "INDEXSERVER_CONFIG_ROLE": "WORKER",
         "NAMESERVER_CONFIG_ROLE": "MASTER 2"
       },
       "STANDBY1_HOSTNAME": {
         "INDEXSERVER_CONFIG_ROLE": "STANDBY",
         "NAMESERVER_CONFIG_ROLE": "MASTER 3"
       }
     }
   }');
   EOF
   

4. Run the update_landscape.sql file:

   hdbsql -i INSTANCE_NUMBER -d SYSTEMDB -u SYSTEM -p 'SYSTEM_PASSWORD' -I update_landscape.sql
   

   Replace SYSTEM_PASSWORD with the password of the SYSTEM user of your SAP HANA database.

5. Verify that the NameServer Config Role configuration is updated such that the master 2 and master 3 roles are assigned to separate nodes in your system.

   Conventionally, the master 2 role is assigned to the first worker node and the master 3 role is assigned to the first standby node.

   cdpy; python landscapeHostConfiguration.py
   

   The output is similar to the following:

   hana-scaleout-w-failover:hs4adm> cdpy
   hana-scaleout-w-failover:hs4adm> python landscapeHostConfiguration.py
   | Host                       | Host   | Host   | Failover | Remove | Storage   | Storage   | Failover | Failover | NameServer | NameServer | IndexServer | IndexServer | Host    | Host    | Worker  | Worker  |
   |                            | Active | Status | Status   | Status | Config    | Actual    | Config   | Actual   | Config     | Actual     | Config      | Actual      | Config  | Actual  | Config  | Actual  |
   |                            |        |        |          |        | Partition | Partition | Group    | Group    | Role       | Role       | Role        | Role        | Roles   | Roles   | Groups  | Groups  |
   | -------------------------- | ------ | ------ | -------- | ------ | --------- | --------- | -------- | -------- | ---------- | ---------- | ----------- | ----------- | ------- | ------- | ------- | ------- |
   | hana-scaleout-w-failover   | yes    | ok     |          |        |         1 |         1 | default  | default  | master 1   | master     | worker      | master      | worker  | worker  | default | default |
   | hana-scaleout-w-failoverw1 | yes    | ok     |          |        |         2 |         2 | default  | default  | master 2   | slave      | worker      | slave       | worker  | worker  | default | default |
   | hana-scaleout-w-failoverw2 | yes    | ok     |          |        |         3 |         3 | default  | default  | slave      | slave      | worker      | slave       | worker  | worker  | default | default |
   | hana-scaleout-w-failoverw3 | yes    | ok     |          |        |         4 |         4 | default  | default  | slave      | slave      | worker      | slave       | worker  | worker  | default | default |
   | hana-scaleout-w-failoverw4 | yes    | ignore |          |        |         0 |         0 | default  | default  | master 3   | slave      | standby     | standby     | standby | standby | default | -       |
   overall host status: ok
   | hana-scaleout-w-failover:hs4adm>

6. To reflect the changes that you've made in the preceding sections, stop and start your SAP HANA database.

Connect to SAP HANA

Because the instructions in this guide didn't set up an external IP address for SAP HANA, you can connect to the SAP HANA instances only through a bastion instance by using SSH, or through SAP HANA Studio.

• To connect to SAP HANA through the bastion instance, connect to the bastion host, and then to the SAP HANA instances by using an SSH client of your choice.

• To connect to the SAP HANA database through SAP HANA Studio, use a remote desktop client to connect to the Windows Server based compute instance. After connecting to this instance, install SAP HANA Studio and access your SAP HANA database.

Enable SAP HANA Fast Restart option

The SAP HANA Fast Restart option reduces the restart time in the event that SAP HANA terminates while the operating system remains running. Google Cloud recommends that you enable this option for your SAP HANA workload, especially for multi-terabyte workloads. For more information about this option, see the SAP document SAP HANA Fast Restart Option.

Perform a failover test

After you have verified that the SAP HANA scale-out system is successfully deployed, test the failover function.

The following instructions trigger a failover by switching to the SAP HANA operating system user and entering the HDB stop command. The HDB stop command initiates a graceful shutdown of SAP HANA and detaches the disks from the host, which enables a relatively quick failover.

To perform a failover test, complete the following steps:

1. Connect to the compute instance of a worker host by using SSH. You can connect from the Compute Engine VM instances page by clicking the SSH button for each compute instance, or you can use your preferred SSH method.

   Go to VM instances

2. Switch to the SAP HANA operating system user:

   su - SID_LCadm

   Replace SID_LC with the value that you specified for the sap_hana_sid argument in your Terraform configuration file. In the example configuration shown in a preceding section of this document, the SID is HS4.

3. Simulate a failure by stopping SAP HANA:

   HDB stop

   The HDB stop command initiates a shutdown of SAP HANA, which triggers a failover. During the failover, the disks are detached from the failed host and reattached to the standby host. The failed host is restarted and becomes a standby host.

4. After allowing time for the takeover to complete, connect to the host that took over for the failed host by using SSH.

5. Switch to the root user:

   sudo su -

6. Display the disk file system information:

   df -h

   Your output is similar to the following example. Note that the /hana/data and /hana/log directories from the failed host are now mounted to the host that took over.

   hana-scaleout-w-failoverw4:~ # df -h
   Filesystem                         Size  Used Avail Use% Mounted on
   /dev/sda3                           45G  7.2G   38G  16% /
   devtmpfs                           4.0M  8.0K  4.0M   1% /dev
   tmpfs                              154G     0  154G   0% /dev/shm
   efivarfs                           256K   26K  226K  11% /sys/firmware/efi/efivars
   tmpfs                               41G   50M   41G   1% /run
   tmpfs                              1.0M     0  1.0M   0% /run/credentials/systemd-tmpfiles-setup-dev-early.service
   tmpfs                              1.0M     0  1.0M   0% /run/credentials/systemd-tmpfiles-setup-dev.service
   tmpfs                              1.0M     0  1.0M   0% /run/credentials/systemd-vconsole-setup.service
   /dev/sda2                           20M  3.9M   17M  20% /boot/efi
   tmpfs                              1.0M     0  1.0M   0% /run/credentials/systemd-tmpfiles-setup.service
   tmpfs                              1.0M     0  1.0M   0% /run/credentials/systemd-sysctl.service
   tmpfs                              1.0M     0  1.0M   0% /run/credentials/serial-getty@ttyS0.service
   tmpfs                              1.0M     0  1.0M   0% /run/credentials/getty@tty1.service
   /dev/mapper/vg_hana_usrsap-usrsap   32G  860M   32G   3% /usr/sap
   10.142.81.194:/hana_shared         1.0T   62G  963G   7% /hana/shared
   tmpfs                               21G  8.0K   21G   1% /run/user/0
   10.55.104.130:/hana_backup         1.0T     0  1.0T   0% /hanabackup
   tmpfs                               21G  8.0K   21G   1% /run/user/1000
   /dev/mapper/vg_hana_data-data      414G  8.1G  406G   2% /hana/data/HS4/mnt00002
   /dev/mapper/vg_hana_log-log        104G  5.1G   99G   5% /hana/log/HS4/mnt00002

7. In SAP HANA Studio, open the Landscape view of the SAP HANA system to confirm that the failover over was successful:

   • The status of the hosts involved in the failover must be INFO.
   • The Index Server Role (Actual) column must show the failed host as the new standby host.

Verify that SAP Host Agent is receiving metrics

To verify that the infrastructure metrics are collected by Google Cloud's Agent for SAP and sent correctly to the SAP Host Agent, follow these steps:

1. In your SAP system, enter transaction ST06.

2. In the overview pane, check the availability and content of the following fields for the correct end-to-end setup of the SAP and Google monitoring infrastructure:

   • Cloud Provider: Google Cloud Platform
   • Enhanced Monitoring Access: TRUE
   • Enhanced Monitoring Details: ACTIVE

Perform post-deployment tasks

Before you use your SAP HANA system, Google Cloud recommends that you perform the following post-deployment tasks:

1. Change the temporary passwords for the SAP HANA system administrator and database superuser.

2. Update the SAP HANA software with the latest patches.

3. If your SAP HANA system is deployed on a VirtIO network interface, then we recommend that you ensure the value of the TCP parameter /proc/sys/net/ipv4/tcp_limit_output_bytes is set to 1048576. This modification helps improve the overall network throughput on the VirtIO network interface without affecting the network latency.

4. Install any additional components such as Application Function Libraries (AFL) or Smart Data Access (SDA).

5. If you are upgrading an existing SAP HANA system, then load the data from the existing system either by using standard backup and restore procedures or by using SAP HANA system replication.

6. Configure and back up your new SAP HANA database. For more information, see the SAP HANA operations guide.

For more information about these tasks, see SAP HANA server installation and update guide.

What's next

• To operate SAP HANA, or the underlying compute instances, see SAP HANA operations guide.
• Automate continuous validation checks for your SAP HANA scale-out system by using Workload Manager. For more information, see About Workload Manager evaluation.
• Set up observability for your SAP HANA to improve by using Workload Manager. For more information, see SAP observability overview.