Relocating Running Systems and Instances
You relocate an instance or a set of instances from one host to another, either physically, or virtually in either direction. The operation retains the status of the instances. Running instances are stopped, unprepared, prepared, and started.
Prerequisites
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The general prerequisites for instance operations have been met.
For more information, see General Prerequisites for Instance Operations.
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Optional: You have specified a preferred host.
For more information, see Setting a Preferred Host for an Instance.
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The technical users associated with the instances to be relocated are available on the target host as well.
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You have set up a flexible license mechanism.
Relocating the SAP instance including the message server (CI or ASCS) invalidates the system license because the host name changes. Therefore the flexible license mechanism does not bind the license to the message server host of the SAP system but instead to a fixed SAP Host Agent within the landscape.
For more information, see Flexible License Mechanism.
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The instance status is Running.
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You have ensured that all instances on which your current instance depends are running.
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If you want to relocate to another operating system version, the target operating system version is not configured by default. Ensure that the operating system versions are configured in the Required Host Type section of the instance properties.
For more information, see:-
SAP Note 2427183 - Relocate instance to different Operating System Version
- Specifying Host Types for Instances
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If you relocate SAP instances connected to an SAP HANA database, ensure that you have installed the hdbclient with the -H <virtual-hostname> option. If this is not the case, the hdbuserstore entry is only generated for the current physical host. Check the<hdbclient-dir>/install/installation.ini. This file must contain an HOSTNAME=<virtual-hostname> entry.
For more information, see Secure User Store (hdbuserstore) in the SAP HANA Security Guide at https://help.sap.com/viewer/b3ee5778bc2e4a089d3299b82ec762a7/latest/en-US/dd95ac9dbb571014a7d7f0234d762fdb.html.
Context
You can relocate instances either on the entire system or on an individual instance. So you can flexibly decide if you want to relocate only one host (for example, in the case of a host outage) or relocate all hosts in the system (for example, in the case of a system scale up).
Ensure that you understand the difference of the following stop operations and the shutdown options before you execute the operation.
By default, SAP Landscape Management performs a soft shutdown for database instances and a hard shutdown for other instances not representing a database. You can change the default settings under .
Stop Operations |
Description |
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Stop |
Stops an instance. Possible shutdown options:
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Forced Stop |
Stops an instance while ignoring intersystem and intrasystem dependencies. You can perform a forced stop also for instances with status Unknown. Possible shutdown options:
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Graceful Shutdown |
Stops an ABAP application server instance in the timeout specified and informs all logged users for shutdown. For more information, see Using Graceful Shutdown. |
Shutdown Option |
Description |
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Soft Shutdown |
Checks for open database connections. If any database connection is open, cancels the operation. Default option for database instances. |
Hard Shutdown |
Ignores open database connections and stops an instance immediately. Default option for instances not representing a database. |
Procedure
Results
- Stops the instance.
- Sets the instance status to Not Running.
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- For database instances:
- Unregisters the database from the operating system.
- Detaches the database from the host. That is, stops the database listeners, if necessary.
- Creates configuration files required for an attach process during a prepare operation.
- For SAP instances that do not represent a database:
- Stops the instance agent
- Unregisters the instance agent from the operating system.
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For Unix-like systems: Removes the agent from file /usr/sap/sapservices
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For Windows systems: Removes the agent from the Windows service registry
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- For custom instances:
- Performs necessary actions to unregister the instance on the host.
- Calls operation acc_<custom instance type>_detach.
- No processes of the custom instances are running.
- For database instances:
- Unbinds virtual IP addresses or unmounts the file systems configured.
If the potential SAP HANA master node is relocated and there are tenants with virtual hostnames registered on this host, they will be unbound.
When you unprepare an SAP HANA tenant database node:-
Checks if this node is a potential master host.
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If the node is a potential master host, unprepares the virtual hostnames of all tenants which have virtual hostnames registered on the SAP HANA tenant database node.
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- Calls the storage adapter or virtualization adapter to unprepare the IP addresses.
- The instance status is Initial.
- Receives service port bindings needed for an attach operation.
- Calls the storage adapter or the virtualization adapter to prepare the IP addresses.
- Binds virtual IP addresses and mounts the file systems configured.
When you prepare an SAP HANA tenant database node:
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Checks if this node is a potential master host.
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If the node is a potential master host, prepares the virtual hostnames of all tenants which have virtual hostnames registered on the SAP HANA tenant database node.
If the potential SAP HANA master node is relocated and there are tenants with virtual hostnames that need to be registered on this master node, they will be bound.
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- For database instances:
- If database instances were unprepared using SAP Landscape Management, writes the respective service entries if not present.
- Attaches the database to the host. That is, registers the database with the operating system.
- If necessary, starts the database listeners.
- For SAP instances that do not represent a database:
- If an SAP instance was unprepared using SAP Landscape Management, writes the respective service entries if not present.
- Registers the instance agent with the operating
system.
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For Unix-like systems: Adds the agent to file /usr/sap/sapservices
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For Windows systems: Adds the agent to the Windows service registry
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- Starts the instance agent.
- For custom instances:
- Calls operation acc_<custom instance type>_attach.
- Performs the necessary actions to register the instance on the host.
- For database instances:
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The instance status is Not Running.
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Starts the instance or the set of instances.
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The instance status is Running.
Next Steps
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You can manage activities related to the operation that is currently running.
For more information, see Performing Operations on Activities.
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You can view the log of all tasks involved in the process.
For more information, see Working with Logs.