Optimize the target system
- Use the latest possible OS with latest patches.
- Use the latest possible DB with latest patches.
- Use the latest possible SAP Kernel with latest patches (for example, upgrade from 7.45 kernel to 7.49 or 7.53).
- Consider using the largest available Azure Virtual Machine. The virtual machine type can be lowered to a smaller virtual machine after the Import process
- Create multiple transaction log files with the first transaction log file on the local non-persistent SSD. Additional transaction log files can be created on P50 disks. VLDB migrations could require more than 5 TB of transaction log space. It's recommended to ensure there's always a large amount of transaction log space is always free (20% is a safe figure). Extending transaction log files during an import isn't recommended and impacts performance.
- SQL Server max degree of parallelism (MAXDOP) should usually be set to 1. Only certain index build operations benefit from MAXDOP and then only for specific tables.
- Accelerated Networking is mandatory for DB and R3load servers.
- Limit the maximum memory a single SQL Server query can request with Resource Governor. The memory limit is needed to prevent index build operations from requesting very large memory grants.
- Secondary indexes for very large tables can be removed from the STR file and built ONLINE with scripts after the main portion of the import has finished and post-processing tasks such as configuring STMS are occurring.
- Customers using SQL Server TDE are recommended to pre-create the database and transaction log files, then enable TDE prior to starting the import. TDE runs for a similar amount of time on a DB that's full of data or empty. Enabling TDE on a VLDB can lead to blocking/locking issues and it's recommended to import into a TDE database. The overhead importing to a TDE database is relatively low.
Cost optimizations
- When you shut down an Azure Virtual Machine and the virtual machine is deallocated, you no longer have to pay for it (only for storage). With pay-as-you-go pricing, snoozing a typical SAP virtual machine provides considerable savings, as much as ~60-70%.
- For Virtual Machines that need to run all or most of the time, use Azure Reserved Virtual Machine Instances. Reserving an instance for one year can provide savings of ~40-45% or as much as ~60-65% for a 3-year reservation.