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)

LOGICAL_SECTOR_SIZE

NUMBER

This column represents the logical sector size value of the disk group in bytes. This is the smallest possible I/O that can be done in this disk group. Any I/O smaller than the logical sector size will cause an assert in the code.

If the value of the LOGICAL_SECTOR_SIZE column is 512, while the value in the SECTOR_SIZE column is 4096, then the disk group supports 512 sector size emulation. This means that I/O operations can be both 512 or 4096 aligned. For example, this means that you can have redo log files with a file block size of 512 bytes in this disk group that can be both read and written to, as well as create new redo log files with a file block size of 4096 bytes.

BLOCK_SIZE

NUMBER

Oracle ASM 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:

• CONNECTED - Disk group is in use by the database instance

• BROKEN - Database instance lost connectivity to the Oracle ASM instance that mounted the disk group

• UNKNOWN - Oracle ASM instance has never attempted to mount the disk group

• DISMOUNTED - Disk group was cleanly dismounted by the Oracle ASM instance following a successful mount

• MOUNTED - Instance is successfully serving the disk group to its database clients

• QUIESCING - CRSCTL utility attempted to dismount a disk group that contains the Oracle Cluster Registry (OCR). The disk group cannot be dismounted until Cluster Ready Services (CRS) exits, because the disk group contains the OCR.

TYPE

VARCHAR2(6)

Redundancy type for the disk group:

• EXTERN

• NORMAL

• HIGH

TOTAL_MB

NUMBER

Total capacity of the disk group (in megabytes)

FREE_MB

NUMBER

Unused capacity of the disk group (in megabytes)

HOT_USED_MB

NUMBER

Number of used megabytes in the hot region

COLD_USED_MB

NUMBER

Number of used megabytes in the cold region

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

COMPATIBILITY

VARCHAR2(60)

Minimum software version required for an Oracle ASM instance to mount this disk group

DATABASE_COMPATIBILITY

VARCHAR2(60)

Minimum software version required for a database instance to use files in this disk group

VOTING_FILES

VARCHAR2(1)

Indicates whether the disk contains voting files (Y) or not (N)

CON_ID

NUMBER

The ID of the container to which the data pertains. Possible values include:

• 0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.

• 1: This value is used for rows containing data that pertain to only the root

• n: Where n is the applicable container ID for the rows containing data

For this view, the value is always 0.