Automatic Storage Management

5-26. What is ASM?

• Is a portable and high-performance cluster file system
• Manages Oracle database files
• Spreads data across disks to balance load
• Mirrors data
• Solves many storage management challenges
• Allows increasing the size of DB without having to shut down the DB to adjust storage allocation

5-27. ASM: Key Features and Benefits

• Stripes files, but not logical volumes
• Provides online disk reconfiguration and dynamic rebalancing
• Allows for adjustable rebalancing speed
• Provides redundancy on a per-file basis (rather than on a volume basis)
  
• Supports only Oracle database files (data files, log files, control files, archive logs, Recovery Manager (RMAN) backup sets, etc)
  
• Is cluster aware (so there's no need for a Cluster Logical Volume Manager or a Cluster File System)
  
• Is automatically installed
  

5-28. ASM: Concepts

• ASM disk group
• ASM file
• ASM disk
• Allocation unit
• Physical block