Configuration and tuning of database workloads

If the cluster is focused on database workloads such as SAP HANA/DB2® DPF/DashDB or DIO/AIO, the following configuration options must be tuned:
Configuration Default Value Recommended Comment
enableLinuxReplicatedAio N/A Yes The default value depends on the release of IBM Storage Scale.
preStealPct 1 See below Only for Direct I/O.
Database workload customers using direct I/O must also enable the following preStealPct tuning depending on the IBM Storage Scale levels:
  • 3.5 (any PTF level)
  • 4.1.1 (below PTF 10)
  • 4.2.0 (any PTF level)
  • 4.2.1 (below PTF 2).
The database workload customers with direct I/O enabled who are running older code levels must tune preStealPct as follows:
echo 999 | mmchconfig preStealPct=0 -i
After upgrading to IBM Storage Scale from one of the previously referenced older code levels to a higher level (especially 4.1.1 PTF 10, 4.2.1 PTF 2, or 4.2.2.0 or higher), you can set the configuration option preStealPct=0 to its default value as follows:
echo 999 | mmchconfig preStealPct=1 -i