Hi @Anchal gupta ,
You can follow the official Microsoft documentations below for migrating/moving the SCOM database and data warehouse:
Moving the Operational Database
https://video2.skills-academy.com/en-us/previous-versions/system-center/system-center-2012-r2/hh278848(v=sc.12)
How to Move the Data Warehouse Database
https://video2.skills-academy.com/en-us/previous-versions/system-center/system-center-2012-r2/hh268492(v=sc.12)
If you want some guides, you'll find some here:
Migrating Operations Manager 2012 R2 Databases to New Database Server
SCOM 2012 R2 – Moving the operationsmanager DB from SQL server to new SQL Cluster
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Best regards,
Leon