My Oracle Support Banner

Understanding ASM Capacity and Reservation of Free Space in Exadata (Doc ID 1551288.1)

Last updated on APRIL 05, 2024

Applies to:

Oracle Database Cloud Service - Version N/A and later
Oracle Exadata Storage Server Software
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Information in this document applies to any platform.


This note discusses the concepts of ASM disk group failure coverage, how to reserve free space to cover disk or cell failure in an Exadata environment, and how to determine the resulting capacity of a disk group (DG).


This applies primarily to Exadata which uses ASM for storage management.  This information is intended for architects, database, and systems administrators who will plan and manage storage in the Exadata environment.  It is believed that the concepts apply to non-Exadata environments, but the assertions in this note have not been tested in non-Exadata environments.


To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!

In this Document
 ASM redundancy types
 Failure Coverage
 Calculating Reserve Space and Disk Group Capacity
 Calculating Reserve Space for Failure Coverage
 Exadata Smart Rebalance for High Redundancy Disk Groups
 Considerations when Adding Space to an Existing Disk Group
 Oracle Cloud Considerations
 Additional Considerations
 List of Recommended Bug Fixes

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.