Home > Workload Solutions > SAP > Guides > SAP HANA TDI Guides > Dell Validated Design for SAP HANA TDI with Dell PowerStore Storage > SAP HANA capacity requirements
When the SAP HANA nodes boot from a volume on PowerStore, which is referred to as booting from SAN, the required capacity for the operating system must be included in the overall capacity calculation for the SAP HANA installation. Every SAP HANA node requires approximately 100 GB capacity for the operating system, including space for the /usr/sap/ directory.
For more information, see the Dell EMC Host Connectivity Guide for Linux.
SAP HANA persistence (data and log)
The SAP HANA in-memory database requires disk storage to:
Every SAP HANA scale-up or scale-out (worker) node requires two disk volumes or file systems to save the in-memory database on disk (data) and to keep a redo log (log). The size of these volumes or file systems depends on the anticipated total memory requirement of the database and the RAM size of the node. To help you prepare the disk sizing, see the SAP HANA Storage Requirements white paper that is attached to SAP Note 1900823: SAP HANA Storage Connector API (access requires SAP login credentials). The size of the data and log devices depends on the database size. Version 2.10 of the white paper provides the following formula to calculate the size of the data volume:
Sizedata = 1.2 x anticipated net disk space for data
where anticipated net disk space is the anticipated total memory requirement of the database plus an additional 20 percent free space. If the database is distributed across multiple nodes in a scale-out cluster, divide the anticipated net disk space by the number of SAP HANA worker nodes in the cluster. For example, if the anticipated net disk space is 2 TB and the scale-out cluster consists of four worker nodes, every node must be assigned a 616 GB data volume:
(2 TB / 4 = 512 GB x 1.2 = 616 GB).
If the anticipated net disk space is unknown at the time of the storage sizing, use the RAM size of the node plus 20 percent free space for a capacity calculation of the datafile system.
Sizedata = 1 x RAM
Note: The preceding calculations are based on in-memory data (hot data). If you are deploying SAP HANA NSE, the size of the data volume must increase with the size of the buffer cache and anticipated warm data.
The size of the log volume depends on the RAM size of the node. The SAP HANA Storage Requirements white paper that is attached to SAP Note 1900823: SAP HANA Storage Connector API provides the following formulas to calculate the minimum size of the log volume:
[systems ≤ 512 GB] Sizeredolog = 1/2 x RAM
[systems > 512 GB] Sizeredolog = (min) 512 GB