Automatic Storage Management !

ASM is a powerful and portable storage manager designed to manage Oracle Database 10g and 11g database files. ASM simplifies storage management so that DBA’s worry less about Oracle Database file layout and management . ASM delivers lower total cost of ownership while increasing storage utilization, all without compromising performance or availability. With ASM, a fraction of the time is needed to manage your database files.


Some important ASM key features are:

· Volume Management
· Database File System with performance of RAW I/O
· Supports clustering (RAC) and single instance
· Automatic data distribution
· Online add/drop/resize disk with automated data relocation
· Automatic file management
· Flexible mirror protection

Basically, ASM is a storage manager designed to manage Oracle Database files with Volume Manager (1MB/128KB striping, Flexible mirroring and Online disk reconfigurations and automatic rebalancing), File System (Even data distribution with optimal performance) and Automatic file management using Oracle Managed Files (OMF).

Files supported by ASM

Only Oracle files are supported:

Data files
Control files
Online redo log files
Archived redo log files
Flash recovery area files
RMAN files (image copy and backup)

 Files not Supported:

ORACLE_BASE files( including alert log, trace files, etc)
CRS voting disk and OCR files
Output data from UTL_FILE
Any user or application specific files(e.g. XML or Java files)
Oracle 9i external table files