My Oracle Support Banner

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

Last updated on NOVEMBER 10, 2022

Applies to:

Oracle Database Exadata Express Cloud Service - Version N/A and later
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Oracle Database - Enterprise Edition - Version to [Release 11.2 to 19]
Oracle SuperCluster Specific Software
Oracle Database Backup 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
 Additional Considerations

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