Migration Process

Figure 1 shows how OMS migrates data.

Figure 1 How OMS works

The migration process is as follows:

1. OMS queries the list of source objects.
2. The source object storage service returns the list of queried objects.
3. OMS queries the metadata of the source objects.
4. The source object storage service returns the metadata of the source objects.
5. OMS queries the metadata of the destination objects.
6. OBS returns the metadata of the destination objects.
7. OMS determines whether source objects need to be migrated based on metadata comparison results.
   

   If you choose to never or always overwrite destination objects with the same names as source objects, steps 5 to 7 will be skipped.

8. OMS queries the data of the source objects.
9. The source object storage service returns the data of the source objects.
10. OMS writes the source objects into OBS.
11. OBS returns write results.
12. OMS queries the metadata of the source objects.
13. The source object storage service returns the metadata of the source objects.
14. OMS queries the metadata of the destination objects.
15. OBS returns the metadata of the destination objects.
16. OMS uses the metadata to verify data integrity and consistency.
17. Steps 3 to 16 are repeated to migrate all objects requested in Step 1.
18. Steps 1 to 17 are repeated to migrate all objects in the migration task.