About SDMI

When planning a release upgrade and executing Software Update Manager (SUM), data migrations are often necessary due to changes in the data structure. Traditionally, these migrations are performed during the upgrade process using XPRAs or XCLA techniques, which extend the system downtime. However, with Silent Data Migration (SDMI), it is now possible to migrate application data during uptime, allowing productive system usage and reducing downtime. The goal of SDMI is to minimize technical downtime for SAP S/4HANA release upgrades or conversions using the SUM tool. It is a data conversion technology implemented in SAP S/4HANA upgrades and conversions starting from the target release S/4HANA 1909 and higher. The shift towards SDMI is driven by the desire to achieve Zero Downtime Upgrades in the future.

For more detailed information on leveraging the Zero Downtime Option of SUM for SAP S/4HANA update/upgrades Zero Downtime Option (ZDO) for SAP S/4HANA

Technical information:

Technical background of Silent Data Migration, how the Silent Data Migration is enabled by the SUM tool, and how to manage users for Silent Data Migration.

The SAP S/4HANA system upgrade or conversion can be divided into several high-level phases:

S/4 N: S/4HANA 1809 and lower S/4 N+1(S/4HANA 1909)

After providing the necessary information to SUM, the system enters the restricted uptime phase. During this phase, business users can still work on the system, but changes to customizing and the ABAP repository are locked. A clone of the ABAP repository is created and upgraded to the target release of SAP S/4HANA.

In the system downtime phase, no business users are logged in, and both the ABAP repository and customizing settings are locked. This is when database schema changes are activated, S/4HANA table content is imported, and AIMs, XPRAs, and XCLAs are executed. However, during the upgrade or conversion to S/4HANA 1909, instead of performing application data migration through XPRAs or XCLAs in the technical downtime, the SUM tool configures the system to perform the data conversion via Silent Data Migration after the upgrade is completed and the system is in business uptime.

Once jobs are released using the program BTCTRNS2 executed the Silent Data Migration starts job SAP_SDM_EXECUTOR_ONLINE_MIGR will be scheduled and start the execution of the SDMI classes with Business uptime

Enabling Silent Data Migration:

Silent Data Migration classes are executed automatically in online mode through the background job SAP_SDM_EXECUTOR_ONLINE_MIGR. This job runs in all clients using a specific step user, also known as the SDMI User. To ensure the silent data migration can run in every client, this technical user must be created. There are three options for creating these users:

Silent Data Migration classes are executed automatically in online mode through the background job SAP_SDM_EXECUTOR_ONLINE_MIGR. This job runs in all clients using a specific step user, also known as the SDMI User. To ensure the silent data migration can run in every client, this technical user must be created. There are three options for creating these users:

During the SUM upgrade or update, the SDMI user will be created and registered automatically.

After the upgrade, you can create and register the SDMI user using the SDM_USER transaction.

Manually create the SDMI user using SU01 and register it using the SDM_USER transaction.

These SDMI users must be of type ‘SYSTEM.’ For the first two options, the user will receive the SAP_ALL profile. If your company’s security regulations do not allow users with the SAP_ALL profile, you should consider option 3, where you create the user in advance with necessary authorizations as per SAP Note 2850918 – Authorizations required for Silent Data Migration (SDMI) in SAP S/4HANA

During the SUM upgrade or update, a dialog box will prompt you to create a technical user for SDM. Choosing “Yes” allows SUM to create the technical users in each client with a random name following the pattern SDMI_xxxxxxxxxxxx (Option 1). Selecting “No” means that SUM will not create a technical user in clients where it is missing, and a message will be generated in the update log during the post-processing phase.

The SDM_USER transaction can be used to create and register a technical user for SDMI in the current client. You can either generate an SDMI user with a random name or input a preferred username with the necessary authorizations.

This is a user Management screen using the transaction SDM_USER.

To view all the registered SDMI users in each client, you can access the SDMI user in all clients.

After creating and registering the SDMI users, the system triggers the background job SAP_SDM_EXECUTOR_ONLINE_MIGR, which executes the Silent Data Migration classes qualified in the target release using PFW. This job runs every 30 minutes by default and picks up unfinished SDMI classes, re-triggering the migration process. The actual data migration is carried out by dialog work processes in the form of packages or portions.