Call now: 252-767-6166  
Oracle Training Oracle Support Development Oracle Apps

 E-mail Us
 Oracle Articles
New Oracle Articles

 Oracle Training
 Oracle Tips

 Oracle Forum
 Class Catalog

 Remote DBA
 Oracle Tuning
 Emergency 911
 RAC Support
 Apps Support
 Oracle Support

 SQL Tuning

 Oracle UNIX
 Oracle Linux
 Remote s
 Remote plans
 Application Server

 Oracle Forms
 Oracle Portal
 App Upgrades
 SQL Server
 Oracle Concepts
 Software Support

 Remote S


 Consulting Staff
 Consulting Prices
 Help Wanted!


 Oracle Posters
 Oracle Books

 Oracle Scripts

Don Burleson Blog 







ASM vs filesystems

Oracle Database Tips by Donald BurlesonNovember 13, 2015

Question:  What are the pros and cons of ASM vs. a plain filesystem?  I want to know the cost and benefits of each approach.  In ASM vs filesystems which would you choose?

Answer:  Both ASM and filesystems have their own advantages and disadvantages and you need to address the following requirements.   Regardless of whether you choose ASM or vanilla filesystems, you still would want to adhere to SAME (stripe and mirror everywhere).  See my notes on the Oracle disk architecture

  • Use filesystems for databases that fit onto one disk:  With the plague of super-large disks, intelligent file placement is important, but when your entire database resides on a single one terabyte disk, striping makes on sense.
  • Use ASM for RAC:  ASM provides a cluster file system manager.
  • Use filesystems if you have disk-level mirroring and striping:  Many disk arrays devices take care of striping and mirroring at the hardware level on your behalf.
  • Size matters:  As a general rule, small databases (under one gig will use filesystems, while very large databases (terabytes) will use ASM.
  • ASM trades complexity for ease of use:  It is very difficult to trace I/O issues with ASM because the mapping of data files to disks is scrambled as RAID 0+1).
  • Use filesystems with SSD:  If you are using solid-state disk devices, it is not necessary to stripe or mirror your data and ASM is not needed.

In sum, only use ASM when you have a large complex database that spans many disk spindles and RAID striping is used.

Oracle has another approach in the Oracle 11gr2 "ASM intelligent file placement" feature.

In intelligent file placement the data file is broken down into "hot" and "cold" disk platter areas, leveraging on the fact that the outermost sectors of a disk contain more space per revolution than the inner "cold" sectors.

Get the Complete
Oracle SQL Tuning Information 

The landmark book "Advanced Oracle SQL Tuning  The Definitive Reference"  is filled with valuable information on Oracle SQL Tuning. This book includes scripts and tools to hypercharge Oracle 11g performance and you can buy it for 30% off directly from the publisher.



Burleson is the American Team

Note: This Oracle documentation was created as a support and Oracle training reference for use by our DBA performance tuning consulting professionals.  Feel free to ask questions on our Oracle forum.

Verify experience! Anyone considering using the services of an Oracle support expert should independently investigate their credentials and experience, and not rely on advertisements and self-proclaimed expertise. All legitimate Oracle experts publish their Oracle qualifications.

Errata?  Oracle technology is changing and we strive to update our BC Oracle support information.  If you find an error or have a suggestion for improving our content, we would appreciate your feedback.  Just  e-mail:  

and include the URL for the page.


Burleson Consulting

The Oracle of Database Support

Oracle Performance Tuning

Remote DBA Services


Copyright © 1996 -  2020

All rights reserved by Burleson

Oracle ® is the registered trademark of Oracle Corporation.



Oracle Training at Sea
oracle dba poster

Follow us on Twitter 
Oracle performance tuning software 
Oracle Linux poster