Thursday, January 28, 2010

ACFS: NOT for Database Files!

ASM Cluster File System was introduced with Grid Infrastructure along with Oracle 11g Release 2. To be honest, I assumed this file system layer was also provided to store database files, a kind of improvement, because ASM, being a black box to many, 'hided' these database files from sight on the Operating System. Which - on the other side - was kind of neat, because chances were lowered these files to be accidentally removed by non-knowledgable users.

It is technically possible to store your database files on ACFS, no question about that. I already deployed a number of test databases on ACFS. However, the Oracle 11g Release 2 Storage Administrator's Guide, Chapter 5 states:

  • Oracle ASM is the preferred storage manager for all database files. It has been specifically designed and optimized to provide the best performance for database file types.

  • Oracle ACFS is the preferred file manager for non-database files. It is optimized for general purpose files.

  • Oracle ACFS does not support any file that can be directly stored in Oracle ASM.

    Not supported means Oracle Support Services will not take calls and development will not fix bugs associated with storing unsupported file types in Oracle ACFS.

Especially that last sentence says it all: If you run into trouble with your database stored on ACFS, you will not be assisted by Oracle Support.

Here is the list of file types that are NOT supported to be stored on ACFS:

Control files
Data files
Redo log files
Archive log files
Temporary files
Data file backup pieces
Data file incremental backup pieces
Archive log backup piece
Data file copy
Persistent initialization parameter file (SPFILE)
Flashback logs
Change tracking file
Data Pump dumpset
Automatically generated control file backup
Cross-platform transportable data files
Flash file
Oracle ASM Persistent initialization parameter file (SPFILE)
Oracle Cluster Registry file

Be aware of this when you are designing your Grid Infrastructure!

Tuesday, January 19, 2010

UKOUG RAC & HA SIG Meeting Agenda Available

On February 10 I will present at the UKOUG RAC & HA SIG meeting at Oracle in Reading.
The agenda has been published and will contain the following interesting sessions:

Welcome and Introduction

Support Roundup - Phil Davies, Oracle

Recovery of very Large Database in shortest time possible - Arnoud Roth, Inter Access

ASM Split Brain - Problem Description - Pavel Rabel, DSP Managed Services

Application Consolidation Experiences on a 3-node RAC Cluster - Martin Bach, Markit Group Ltd.

Using RAC and Grid for Database Consolidation - Panel Discussion

Rolling Database Upgrade, a Real World Experience - Thomas Ramanauskas, ekc

Oracle RAC on Cisco UCS hardware, boxes to blades by brunch - Dev Nayak, DSP Managed Services and Carl Bradshaw, Cisco

Stretched RAC Cluster with 11gR2, David Burnham, Ioko365


Looks to be a promising day!
I am really looking forward being there.