When the SnapCenter plug-in hosts require refresh, you should move the resources from old host to new host. When the new host is added to SnapCenter, it will discover all the resources but will be treated as new resources.

About this task

You should run the API or cmdlet which will take old host name and new host name as input, compare the resources by name, and relink the objects of matching resources from old host to new host. The matching resources will be marked as protected.

The IsDryRun parameter is set to True by default and this identifies the matching resources of the old and new host.

After verifying the matching resources, you should set the IsDryRun parameter to False to relink the objects of the matching resources from the old host to new host.
The AutoMigrateManuallyAddedResources parameter is set to True by default and this automatically copies the manually added resources from old host to the new host.

The AutoMigrateManuallyAddedResources parameter is applicable only for Oracle and SAP HANA resources.
The SQLInstanceMapping parameter should be used if the instance name is different between old host and new host. If it is a default instance then use default_instance as instance name.

Tech refresh is supported for the following SnapCenter Plug-ins:

SnapCenter Plug-in for Microsoft SQL Server
- If the SQL databases are protected at instance level and as part of host tech refresh only partial resources are moved to new host, then the existing instance level protection will be converted to resource group protection and instances from both the hosts will be added to the resource group.
- If a SQL host (for example host1) is used as either scheduler or verification server for resources of another host (for example host2), then while performing tech refresh on host1, the schedule or the verification details will not be migrated and will continue to run on host1. If you have to modify, then you should manually change it in the respective hosts.
- If you are using SQL Failover Cluster Instances (FCI) setup, you can perform the tech refresh by adding the new node to the FCI cluster and refreshing the plug-in host in SnapCenter.
- If you are using SQL Availability Group (AG) setup, tech refresh is not required. You can add the new node to AG and refresh the host in SnapCenter.
SnapCenter Plug-in for Windows
SnapCenter Plug-in for Oracle Database

If you are using Oracle Real Application Cluster (RAC) setup, you can perform the tech refresh by adding the new node to the RAC cluster and refreshing the plug-in host in SnapCenter.
SnapCenter Plug-in for SAP HANA Database

The supported use cases are:

Migrating resources from one host to another host.
Migrating resources from multiple hosts to one or fewer hosts.
Migrating resources from one host to multiple hosts.

The supported scenarios are:

New host has a different name from the old host
Existing host has been renamed

Before you begin

As this workflow modifies the data in SnapCenter repository, it is recommended to backup the SnapCenter repository. Incase of any data issues, SnapCenter repository can be reverted to old state using the backup.

For more information, refer to Back up the SnapCenter repository.

Steps

Deploy the new host and install the application.
Suspend the schedules of the old host.
Move the required resources from the old host to the new host.
1. Bring up the required databases in the new host from the same storage.
  - Ensure that the storage is mapped to the same drive or same mount path as that of old host. If the storage is not mapped correctly, backups created in old host cannot be used for restore.
    
    By default, Windows auto assigns the next available drive.
  - If storage DR is enabled, the respective storage should be mounted in the new host.
2. Check for the compatibility if there is a change in application version.
3. Only for Oracle plug-in host, ensure that the UIDs and GIDs of Oracle and it’s group users are same as that of old host.
Add the new host to SnapCenter.
Verify if all the resources are discovered.

Run the host refresh API: /5.0/techrefresh/host or the cmdlet: Invoke-SmTechRefreshHost.

The dry run is enabled by default and the matching resources to be relinked are identified. You can verify the resources by running either the API: '/jobs/{jobid}' or the cmdlet Get-SmJobSummaryReport.

If you have migrated the resources from multiple hosts, you should run the API or the cmdlet for all the hosts. If the drive or mount path in the new host is not same as the old host, following restore operations will fail:

SQL in-place restore will fail. However, RTAL feature can be leveraged.
Restore of Oracle and SAP HANA databases will fail.

If you want to migrate to multiple hosts, you should perform all the steps from step 1 for all the hosts.

You can run the API or cmdlet on the same host multiple times, it will relink only if there is a new resource identified.

(Optional) Remove the old host or hosts from SnapCenter.

Related information

For information on the APIs , you need to access the Swagger page. see How to access REST APIs using the swagger API web page.

The information regarding the parameters that can be used with the cmdlet and their descriptions can be obtained by running Get-Help command_name. Alternatively, you can also refer the SnapCenter Software Cmdlet Reference Guide.