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The Sign-Off Table

Lesson 2 of 5

DMO variants

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Standard DMO assumes the source and target databases sit close together and the application server stays on its host. Real projects are messier: the operating system may not be supported on the target release, the company may be leaving its own data center, or the software level may not need to change at all. SAP offers several DMO variants for these situations.

VariantWhat it doesKey constraints
Standard DMOUpdate or conversion plus migration, in placeSource and target in the same data center; SAP's deck says DMO is not supported across data centers because of latency
DMO without system updateMigration only, no software changeSAP's deck lists SAP HANA as the target for this use case
DMO with system moveMoves the whole system: new PAS host, other data center or cloud infrastructureTarget database and PAS set up before the run; export to files, no pipe mode; target SAP HANA or SAP ASE
Move variant for S/4HANA conversion (DMOVE2S4)A move variant specifically for conversion to SAP S/4HANACheck the current DMO note for prerequisites; can be combined with downtime-optimized DMO
SUM on an additional application serverRuns SUM and R3load on the host with the best resourcesRestrictions listed in the DMO note
DMO variants as described on SAP's DMO page and in SAP's DMO tuning deck. Always confirm against the DMO note for your SUM support package.
The Sign-Off Table · thesignofftable.com/academy/sap-bas-302

DMO with system move

DMO with system move lets the landscape change during the run. Before SUM starts, the target SAP HANA database and the target PAS (and ASCS) are installed and configured; SAP PRESS notes that they are installed from SAP S/4HANA installation media for a conversion. SUM runs first on the original PAS and exports the database into compressed files in the SUM directory, so plenty of disk space is needed there. The SUM directory is then transferred to the target host, where SUM continues and imports. Because the data goes through files rather than through pipes, this variant does not use R3load pipe mode.

  1. Target preparedSAP HANA database, ASCS and PAS installed in the target data center
  2. Uptime on sourceSUM runs on the original PAS; shadow processing
  3. Export in downtimeApplication data exported to compressed files in the SUM directory
  4. TransferSerial: export finishes, then the directory is copied · Parallel: files copied while export continues, synchronized until complete
  5. Import on targetSUM continues on the target PAS and imports into SAP HANA
  6. Finish on targetRemaining update or conversion phases on the target host
DMO with system move. Parallel transfer saves time but needs careful synchronization.
The Sign-Off Table · thesignofftable.com/academy/sap-bas-302

The transfer mode is a real downtime lever. In serial mode the export completes locally before the SUM directory is copied, which is simple but adds the full copy time to downtime. In parallel mode the directory is transferred first and SUM runs on both hosts at the same time, with files copied as they are produced; this overlaps export, transfer and import but must be synchronized until every file has arrived.

Parallel transfer mode in DMO with system move: export, file transfer and import overlap, and SUM keeps both hosts synchronized until every file has arrived.
The Sign-Off Table · thesignofftable.com/academy/sap-bas-302

Choosing a variant

  • Same data center, supported OS: standard DMO.
  • Only the database should change, no new release: DMO without system update.
  • New hosts, unsupported OS, or a move to another data center or cloud: DMO with system move or the move variant for S/4HANA conversion.
  • Moving into RISE: the approach is agreed with SAP ECS, which executes the technical conversion and the separately ordered DMO under the contract.
Picking a DMO variant from the situation; under RISE the choice is agreed with SAP ECS.
The Sign-Off Table · thesignofftable.com/academy/sap-bas-302

What would you do?

Contoso's EP1 runs in Contoso's own Detroit data center; CMP will run in the private cloud landscape SAP ECS operates. A junior admin suggests standard in-place DMO with the target SAP HANA database in the cloud, because it uses pipe mode and is faster. What should Sam say?

Key points
  • Standard DMO is in place and not supported across data centers because of latency.
  • DMO without system update migrates only, with SAP HANA as the target.
  • DMO with system move installs the target first, exports to files (no pipe mode) and continues on the target host; transfer is serial or parallel.
  • A move variant for S/4HANA conversion exists; under RISE, the variant is agreed with SAP ECS.

Check your understanding · not graded

Lesson check

  1. 1. Which DMO variant migrates the database without changing the software level?

  2. 2. What must exist before DMO with system move starts?

  3. 3. In parallel transfer mode for DMO with system move, what happens?

  4. 4. Why does a move variant need extra infrastructure testing?