Querying ASM Disk Information in Oracle

SQL Code

1select  name
2,       group_number
3,       disk_number
4,       total_mb
5,       free_mb
6from    v$asm_disk
7order   by group_number
8/

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, capacity, and available space.
• Facilitates storage management, monitoring, and capacity planning.

Breakdown:

SQL

select name, group_number, disk_number, total_mb, free_mb
from v$asm_disk
order by group_number
/

Key Points:

• select name, group_number, disk_number, total_mb, free_mb: Specifies the columns to extract 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.
  • total_mb: Total storage capacity of the disk in megabytes.
  • free_mb: Available space on the disk in megabytes.

• from v$asm_disk: Identifies the data source, the dynamic view v$asm_disk that contains ASM disk information.

• order by group_number: Arranges the results based on disk group numbers for enhanced readability and organization.

• /: Terminates the SQL statement for execution.

Insights and Explanations:

• Capacity and Availability: The output highlights available space and total capacity, aiding in storage planning and allocation.

• Monitoring and Troubleshooting: This query supports proactive monitoring of disk usage and identification of potential storage issues.

• Performance Considerations: For larger 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 valuable tool for understanding ASM disk capacity and availability, crucial for effective storage management in Oracle databases.