Hi @SethuRam , welcome to Microsoft Q&A forum.
As per the article, "In Azure SQL Managed Instance copy-only backup cannot be created for a database encrypted with service-managed Transparent Data Encryption (TDE). Service-managed TDE uses internal key for encryption of data, and that key cannot be exported, so you could not restore the backup anywhere else. Consider using customer-managed TDE instead to be able to create copy-only backups of encrypted databases, but make sure to have encryption key available for later restore."
So firstly we need to use the Customer-managed TDE if we want to take copy-only backup and then we can restore it across subscription as mentioned in the below articles:
Copy-Only Backups - Please note this article explains the process of creating the backup in the local system. However we can use command like below to restore it on Azure Blob Storage:
USE [master] BACKUP DATABASE [SQLTestDB] TO URL = N'https://msftutorialstorage.blob.core.windows.net/sql-backup/sqltestdb_backup_2020_01_01_000001.bak' WITH COPY_ONLY, CHECKSUM GO
I have not tried this command myself but you can refer to SQL backup and restore to Azure Blob storage service
Restore a database to Azure SQL Managed Instance with SSMS
Please let me know if this helps or else we can discuss further on the same.
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