Visualizing Disk Groups in Oracle ASM with SQL

Note: A group number of zero his indicates that a disk is available but hasn't yet been assigned to a disk group.

SQL Code

 1set lines 100
 2col name	format a10
 3col path 	format a30
 4select	name
 5,	group_number
 6,	disk_number
 7,	mount_status
 8,	state
 9,	path
10from 	v$asm_disk
11order 	by group_number
12/

Sample Oracle Output:

1
2no rows selected
3SQL>

Purpose:

• Retrieves and displays key information about Automatic Storage Management (ASM) disks within the database.
• Provides insights into disk configuration, status, and health.
• Facilitates storage management, monitoring, and troubleshooting.

Breakdown:

SQL

set lines 100
col name format a10
col path format a30
select name, group_number, disk_number, mount_status, state, path
from v$asm_disk
order by group_number
/

Key Points:

Formatting Output:

*   `set lines 100`: Adjusts output display to accommodate 100 lines per page.
*   `col name format a10`: Formats the `name` column to a width of 10 characters.
*   `col path format a30`: Formats the `path` column to a width of 30 characters.

Querying ASM Disk Information:

*   `select name, group_number, disk_number, mount_status, state, path`: Queries specific columns from the `v$asm_disk` view:
    
    *   `name`: Disk name within ASM.
    *   `group_number`: Number of the ASM disk group to which it belongs.
    *   `disk_number`: Unique identifier of the disk within its group.
    *   `mount_status`: Indicates whether the disk is mounted and available.
    *   `state`: Reflects the disk's current state (e.g., NORMAL, OFFLINE).
    *   `path`: Operating system path to the disk.

Ordering Results:

*   `order by group_number`: Arranges the output based on disk group numbers for better organization.

Execution:

*   `/`: Terminates the SQL statement for execution.

Insights and Explanations:

• Key Information: The code highlights essential details about ASM disks, aiding in understanding their configuration, status, and potential issues.

• Monitoring and Troubleshooting: This query is valuable for proactive monitoring of disk health, identifying problems, and troubleshooting storage-related issues.

• Performance Considerations: For large ASM environments, consider using where clauses or filtering techniques to optimize query performance.

• Additional Insights:

  • Explore v$asm_diskgroup for information about disk groups themselves.
  • Use v$asm_file to view files stored on ASM disks.
  • Consider v$asm_operation to monitor ASM operations.

Overall, this SQL code provides a comprehensive tool for examining ASM disk information, crucial for effective storage management in Oracle databases.