SAP HANA is an in-memory database. But it still requires disk storage space — to preserve database information if the system shuts down, either intentionally or due to a power loss, for instance.
Disk sizing can be categorized into
- Persistence Layer (also called Data Volume)
- Disk Log (also called Log Volume)
Persistence Layer (Data Volume):
Data changes in the database are periodically copied to disk to ensure a full image of the business data on disk in Data Volume (Persistence Layer).
The capacity for this storage is calculated based on the total amount of RAM:
Disk Log (Log Volume):
Log Volume saves log files to ensure that changes are durable and the database can be restored to the last committed state after a restart.
The minimum size for the Log Volume
is equal to the size of the SAP HANA server‘s main memory.
Note that the certified hardware configurations already take these rules into account, so there is no need to perform this disk sizing
. However, we still include it here for your understanding.