Purpose

The ALTER IORMPLAN command updates the I/O Resource Management (IORM) plan for the cell.

The ALTER IORMPLAN command clauses control the IORM objective and specify directives that control access to I/O resources.

Syntax

ALTER IORMPLAN [ objective = iorm_objective ]
      [ catplan = { ( directive [, directive] ... ) | "" } ]
      [ dbplan = { ( directive [, directive] ... ) | "" } ]
      [ clusterplan = { ( directive [, directive] ... ) | ""  } ]

Parameters

• objective: Specifies the optimization mode for IORM. The valid objective values are:

  • auto - Use this setting for IORM to determine the best mode based on active workloads and resource plans. IORM continuously and dynamically determines the optimization objective, based on the observed workloads and enabled resource plans. This is the recommended value for most use cases, and starting with Oracle Exadata System Software release 21.2.0, this is the default setting.
  • high_throughput - Use this setting to optimize critical DSS workloads that require high throughput. This setting improves throughput at the cost of I/O latency.
  • low_latency - Use this setting to optimize critical OLTP workloads that require extremely good disk latency. This setting provides the lowest possible latency at the cost of throughput by limiting disk utilization.
  • balanced - Use this setting for a mixture of critical OLTP and DSS workloads. This setting balances low disk latency and high throughput. This setting limits disk utilization of large I/Os to a lesser extent than low_latency to achieve a balance between latency and throughput.
  • basic: Use this setting to limit the maximum small I/O latency and otherwise disable I/O prioritization. This is the default setting in Oracle Exadata System Software release 20.1.0 and earlier.

• catplan: Specifies the category plan, allowing you to allocate resources primarily by the category of the work being done. If no catplan directives are set, then every category has an equal share of the resources by default.

  Note:

  Starting with Oracle Exadata System Software release 25.1.0, the category plan is removed and no longer supported.

  Starting with Oracle Exadata System Software release 21.2.0, the category plan is deprecated, and a warning message is issued when a category plan is specified.

• dbplan: Specifies the interdatabase plan, allowing you to manage resource allocations among databases. If no dbplan directives are set, then every database has an equal share of the resources by default.

• clusterplan: Specifies the cluster plan, allowing you to manage resource allocations among Oracle Grid Infrastructure clusters. If no clusterplan directives are set, then every cluster has an equal share of the resources by default.

  Note:

  The cluster plan is first introduced in Oracle Exadata System Software release 21.2.0.

Usage Notes

• To fully enable any user-defined IORM plans (catplan, dbplan, or clusterplan), the IORM objective must be set to a value other than basic.

• The cluster plan (clusterplan) uses ASM-scoped security for cluster identification. The value of the name attribute must match the asm field in the cellkey.ora file, which is part of the ASM-scoped security definition for the cluster.

• Different user-defined IORM plans inter-operate as follows:

  • The catplan and dbplan can be used in combination only if the dbplan does not contain any directives having type=profile.

    In this case, directives from both plans are applied to determine the share of resources.

  • The catplan and clusterplan cannot be used in combination.

    You cannot set clusterplan directives when catplan directives exist. Likewise, you cannot set catplan directives when clusterplan directives exist.

  • The clusterplan and dbplan can be used in combination only if the dbplan does not contain any allocation or level directives.

    In this case, directives from both plans are applied to determine the share of resources.

• To remove the current directives and reset a catPlan, dbPlan, or clusterplan parameter, set the parameter to an empty string by using a pair of single or double quotation marks. The quotation marks must match. For example, "" is correct, but "' is incorrect.

• Because of the command length and complexity, consider running ALTER IORMPLAN commands by using scripts.

• IORM is configured individually on every storage server using the ALTER IORMPLAN command. To deliver consistent overall system performance, ensure every storage server in the storage cluster uses the same IORM configuration settings.