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).
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