Oracle Cloud Infrastructure Documentation

Managing Exadata DB System I/O Resources

This topic explains the I/O Resource Management (IORM) feature and how to enable it, modify the IORM settings, and disable it by using the Console or the API.

About IORM

The I/O Resource Management (IORM) feature allows you to manage how multiple databases share the I/O resources of an Oracle Exadata DB system.

On an Exadata DB system, all databases share dedicated storage servers which include flash storage. By default, the databases are given equal priority with respect to these resources. The Exadata storage management software uses a first come, first served approach for query processing. If a database executes a major query that overloads I/O resources, overall system performance can be slowed down.

IORM allows you to assign priorities to your databases to ensure critical queries are processed first when workloads exceed their resource allocations. You assign priorities by creating directives that specify the number of shares for each database. The number of shares corresponds to a percentage of resources given to that database when I/O resources are stressed.

Directives work together with an overall optimization objective you set for managing the resources. The following objectives are available:

  • Auto - Recommended. IORM determines the optimization objective and continuously and dynamically determines the optimal settings, based on the workloads observed, and resource plans enabled.
  • Balanced - For 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 good latency and good throughput.
  • High throughput - For critical DSS workloads that require high throughput.
  • Low latency - For critical OLTP workloads. This setting provides the lowest possible latency by significantly limiting disk utilization.

For more information about IORM, see Exadata System Software User's Guide.

Required IAM Policy

To use Oracle Cloud Infrastructure, you must be given the required type of access in a policy  written by an administrator, whether you're using the Console or the REST API with an SDK, CLI, or other tool. If you try to perform an action and get a message that you don’t have permission or are unauthorized, confirm with your administrator the type of access you've been granted and which compartment  you should work in.

For administrators: The policy in Let database admins manage DB systems lets the specified group do everything with databases and related Database resources.

If you're new to policies, see Getting Started with Policies and Common Policies. If you want to dig deeper into writing policies for databases, see Details for the Database Service.

Using the Console

To enable IORM on your Exadata DB system
To modify the IORM configuration on your Exadata DB system

Using the API

For information about using the API and signing requests, see REST APIs and Security Credentials. For information about SDKs, see Software Development Kits and Command Line Interface.

Use these API operations to manage the I/O resources of your Exadata DB system.