I/O Stack configuration for SAP HANA

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Starting with SAP HANA 1.0 SPS10, SAP introduced parameters to adjust the I/O behavior and optimize the database for the file and storage system used.

NetApp conducted performance tests to define the ideal values. The following table lists the optimal values as inferred from the performance tests.

Parameter Value

max_parallel_io_requests

128

async_read_submit

on

async_write_submit_active

on

async_write_submit_blocks

all

For SAP HANA 1.0 up to SPS12, these parameters can be set during the installation of the SAP HANA database, as described in SAP Note 2267798 – Configuration of the SAP HANA Database during Installation Using hdbparam.

Alternatively, the parameters can be set after the SAP HANA database installation by using the hdbparam framework.

SS3adm@stlrx300s8-6:/usr/sap/SS3/HDB00> hdbparam --paramset fileio.max_parallel_io_requests=128
SS3adm@stlrx300s8-6:/usr/sap/SS3/HDB00> hdbparam --paramset fileio.async_write_submit_active=on
SS3adm@stlrx300s8-6:/usr/sap/SS3/HDB00> hdbparam --paramset fileio.async_read_submit=on
SS3adm@stlrx300s8-6:/usr/sap/SS3/HDB00> hdbparam --paramset fileio.async_write_submit_blocks=all

Starting with SAP HANA 2.0, hdbparam is deprecated, and the parameters are moved to the global.ini file. The parameters can be set by using SQL commands or SAP HANA Studio. For more details, refer to SAP note 2399079: Elimination of hdbparam in HANA 2. The parameters can be also set within the global.ini file.

SS3adm@stlrx300s8-6: /usr/sap/SS3/SYS/global/hdb/custom/config>cat global.ini
…
[fileio]
async_read_submit = on
async_write_submit_active = on
max_parallel_io_requests = 128
async_write_submit_blocks = all
…

For SAP HANA 2.0 SPS5 and later, use the setParameter.py script to set the correct parameters.

fc5adm@sapcc-hana-tst-03:/usr/sap/FC5/HDB00/exe/python_support>
python setParameter.py -set=SYSTEM/global.ini/fileio/max_parallel_io_requests=128
python setParameter.py -set=SYSTEM/global.ini/fileio/async_read_submit=on
python setParameter.py -set=SYSTEM/global.ini/fileio/async_write_submit_active=on
python setParameter.py -set=SYSTEM/global.ini/fileio/async_write_submit_blocks=all