Hotsos Symposium Speaker – George Djerdj Srdanov

George Djerdj Srdanov is a new Hotsos Symposium presenter.


George Djerdj SrdanovGeorge is an Oracle Certified Professional with twelve years of Oracle DBA and fifteen years of IT experience. He is the co-author of two university books in the areas of CAD/CAM and Operational Research.

George has three years of experience as a presenter and assistant professor at the University of Novi Sad, Europe. He has given various presentations and held multiple classes on Oracle-related topics for small groups.

George currently works for Verizon Wireless.

Presentation Title

How to Get the Most Out of Your I/O Subsystem?


Many Oracle DBAs look at the layers of the I/O and storage subsystems and feel like they don't have much control. Between OS and array level caches, striping and logical volume managers and the like in modern storage subsystems, it's often difficult to determine what physical drive a given piece of the database is on, and in many cases, we're told it doesn't matter.

In terms of finding out if those pieces are performing as well as they could, it becomes an even bigger headache. Additionally, very often the sysadmins and/or storage admins aren't very Oracle savvy, making discussions difficult at best.

George hopes to share some helpful information that will enable you to meet them on their turf and identify potential areas for improvement.

Topics include:

  • A quick background on Verizon Wireless and history of how this presentation started.
  • An overview of a generic hardware stack including types of caches, cache configurations and settings/options along with the benefits and drawbacks of each (Direct I/O, CIO, etc.).
  • Expected generic norms for various activities (write to disk, read from disk, write to cache, read from cache, etc.).
  • What metrics should you be looking at first? MB/sec, I/O operations per second, latency, etc.
  • Are default values good enough? Which should you look at first and what do they do?
    • Hardware settings: Fiber channel/HBA card settings such as queue depth, max commands
    • Filesystem I/O size: Sectors, pages, blocks, alignment and how these values impact Oracle
    • Oracle parameters: Which settings should you be changing/matching based on your hardware settings?
  • What should your REALISTIC goals be? Not everyone will have Exadata or all datafiles on how should you set expectations?

Presentation Materials

Presentation materials are available online to attendees only.


The speaker schedule is as follows: