V$ASM_DISKGROUP

7.61 V$ASM_DISKGROUP

V$ASM_DISKGROUP displays one row for every Oracle Automatic Storage Management (Oracle ASM) disk group discovered by the Oracle ASM instance on the node.

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)
`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: `BROKEN` - Database instance lost connectivity to the Oracle ASM instance that mounted the disk group `CONNECTED` - Disk group is in use by the database instance `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. `RESTRICTED` - A disk group mounted in this mode can only be seen by this Oracle ASM instance for maintenance purposes `UNKNOWN` - Oracle ASM instance has never attempted to mount the disk group
`TYPE`	`VARCHAR2(6)`	Redundancy type for the disk group: `EXTEND` `EXTERN` `FLEX` `HIGH` `NORMAL`
`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`.

Note:

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.