IBM Support

SAP HANA database backups not showing Deduplication Savings

Question & Answer


Question

Why does the IBM Spectrum Protect server not show any dedup savings when backing up the SAP HANA database.

Cause

Dedup savings can be achieved by increasing the buffer size used by the Data Protection for SAP HANA client for transferring the database backup data. The Buffsize parameter has a default value of 1 MB but can be up to 32 MB. Experimentation has shown that larger buffer sizes yield better dedup savings. However, an 8MB buffer size (BUFFSIZE 8388608) seems to strike a good balance between dedup efficiency and memory consumption. Savings in 70 - 80 % range (from both dedup & compression) have been observed with an 8MB buffer size.

Log backups should still use a small buffer size (e.g. 512KB) for best efficiency. SAP HANA provides the ability to specify different configuration files for data and log backups. See this document for instructions how to use different profiles for data and log backups: https://www.ibm.com/support/pages/node/533927

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Product Synonym

ADSM TSM Spectrum Protect Tivoli Storage Manager

Document Information

Modified date:
17 March 2021

UID

swg21980949