In an Automatic Storage Management instance, V$ASM_DISKGROUP displays one row for every disk group discovered by the Automatic Storage Management instance. In a database instance, V$ASM_DISKGROUP displays one row for every Automatic Storage Management disk group mounted by the local Automatic Storage Management instance.
Cluster-wide number assigned to the disk group (primary key)
Name of the disk group
Physical block size (in bytes)
Automatic Storage Management metadata block size (in bytes)
Size of the allocation unit (in bytes)
State of the disk group relative to the instance:
CONNECTED - Disk group is in use by the database instance
BROKEN - Database instance lost connectivity to the Automatic Storage Management instance that mounted the disk group
UNKNOWN - Automatic Storage Management instance has never attempted to mount the disk group
DISMOUNTED - Disk group was cleanly dismounted by the Automatic Storage Management instance following a successful mount
MOUNTED - Instance is successfully serving the disk group to its database clients
Redundancy type for the disk group:
Total capacity of the disk group (in megabytes)
Unused capacity of the disk group (in megabytes)
Amount of space that is required to be available in a given disk group in order to restore redundancy after one or more disk failures. The amount of space displayed in this column takes mirroring effects into account.
Amount of free space that can be safely utilized taking mirroring into account, and yet be able to restore redundancy after a disk failure
Number of disks in the disk group that are currently offline
Indicates whether the disk group requires a rebalance, for example, if the instance crashed while a rebalance operation was pending (Y) or not (N)
The minimum software version required for an ASM instance to mount this disk group
The minimum software version required for a database instance to use files in this disk group
The GROUP_NUMBER, TOTAL_MB, and FREE_MB columns are only meaningful if the disk group is mounted by the instance. Otherwise, their values will be 0.