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Negative Value for USABLE_FILE_MB in v$asm_diskgroup (Doc ID 1558006.1)

Last updated on OCTOBER 28, 2024

Applies to:

Oracle Database Cloud Schema Service - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Oracle Database Cloud Service - Version N/A and later
Oracle Database - Standard Edition - Version 11.2.0.1 to 21.1 [Release 11.2 to 21.0]
Information in this document applies to any platform.

Symptoms

A negative value for USABLE_FILE_MB is observed in a NORMAL redundancy diskgroup

Example:

NAME - Name of the disk group

TYPE - Redundancy type for the disk group: EXTEND, EXTERN, FLEX, HIGH, NORMAL

TOTAL_MB - Total capacity of the disk group, excluding that of quorum disks (in megabytes)

FREE_MB - Unused capacity of the disk group (in megabytes)

USABLE_FILE_MB - Amount of free space that can be safely utilized taking mirroring into account and yet be able to restore redundancy after a disk failure

V$ASM_DISKGROUP Describes a disk group (number, name, size related info, state, and redundancy type).
This view performs disk discovery every time it is queried. Because performing a discovery is very resource intensive, this view is not recommended for monitoring scripts.

For information about other columns in V$ASM_DISKGROUP please refer to:

 https://docs.oracle.com/en/database/oracle/oracle-database/21/refrn/V-ASM_DISKGROUP.html

Part III Dynamic Performance Views

Oracle® Database
Database Reference
21c
F31274-22

Cause

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