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.
Column | Datatype | Description |
---|---|---|
GROUP_NUMBER |
NUMBER |
Cluster-wide number assigned to the disk group (primary key) |
NAME |
VARCHAR2(30) |
Name of the disk group |
SECTOR_SIZE |
NUMBER |
Physical block size (in bytes) |
BLOCK_SIZE |
NUMBER |
Automatic Storage Management metadata block size (in bytes) |
ALLOCATION_UNIT_SIZE |
NUMBER |
Size of the allocation unit (in bytes) |
STATE |
VARCHAR2(11) |
State of the disk group relative to the instance:
|
TYPE |
VARCHAR2(6) |
Redundancy type for the disk group:
|
TOTAL_MB |
NUMBER |
Total capacity of the disk group (in megabytes) |
FREE_MB |
NUMBER |
Unused capacity of the disk group (in megabytes) |
REQUIRED_MIRROR_FREE_MB |
NUMBER |
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. |
USABLE_FILE_MB |
NUMBER |
Amount of free space that can be safely utilized taking mirroring into account, and yet be able to restore redundancy after a disk failure |
OFFLINE_DISKS |
NUMBER |
Number of disks in the disk group that are currently offline |
UNBALANCED |
VARCHAR2(1) |
Indicates whether the disk group requires a rebalance, for example, if the instance crashed while a rebalance operation was pending (Y ) or not (N ) |
COMPATIBILITY |
VARCHAR2(60) |
The minimum software version required for an ASM instance to mount this disk group |
DATABASE_COMPATIBILITY |
VARCHAR2(60) |
The minimum software version required for a database instance to use files in this disk group |
Note:
TheGROUP_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
.