Oracle 11g RAC database on ASM, ACFS or OCFS2

I see a lot of questions on shared file systems the can used when people move from single instance to Oracle RAC Datab ASE and Grid Infrastructure. The most common question are the following: "should I place archive logs in OCFS2 or ASM or ACFS of 11g?" I ' ll try to clarify this topic below.

First we need to understand a separation between Oracle database files and non-database files.

database files belong to an Oracle Database and include control files, data files, archived logs, online redo log s, etc. 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. The file list supported by Oracle ASM becomes longer with every new version and it includes nowadays also SPFile, RMAN BAC Kupsets and some other file types. You can however use the other GKFX cluster file systems, including OCFS2 to store Oracle RAC database files.

non-database Files is everything that does does belong to database files including Oracle binaries (Oracle_home, etc.). Oracle ACFS is the preferred File Manager for non-database files. It is optimized-purpose files and can be shared across the RAC cluster. You can use both ACFS or the local file system, like EXT3 to store Oracle database binaries (oracle_home).

ACFS is a part of the Oracle Grid Infrastructure. It cannot is used for a root file system, boot file system, or a file system containing the executables for Grid Infrastru Cture. It is also not supported to store in ACFS any files that can be natively stored in ASM; i.e., it isn't supported to store Oracle database files (controlfiles, datafiles, archived logs, online redo logs, etc.) . Also, the Grid Infrastructure Home cannot is installed in ACFS, it must is installed in a separate file system; e.g.; Ext3. You can use the ACFS though for Oracle binaries (oracle_home), but I would not recommend this.

However, and this is new, since Oracle database version 11.2.0.3 archive logs be supported in ACFS. See Details:http://t.co/vot8bmre. I reflected everything in below support matrix.

Why not OCFS2

You can use OCFS2 to store both database file and Oracle database binaries (oracle_home) However Oracle does not recommend Using OCFS2 anymore for RAC systems, for the following reasons:

-OCFS2 and Grid infrastructure (Oracle cluster-ware) is a separate cluster-wares. Therefore you would is running with 2 cluster-wares instead of one.
-OCFS2 won't gain any new functionality in regard of databases. OCFS2 'll is used for Oracle VMS and all new functionalities is more targeted in this direction than for databases.

As a summary, the recommendation of Oracle is clearly to use ASM for database files, and for everything which cannot be pl aced directly in ASM to use ACFS. However OCFS2 'll is continued to being supported (at least at the moment).

Below is a support matrix for Oracle Rac/grid Infrastructure installation

Supported Storage Option	Voting/ocr	GRID Software	Database files	Database Software
Automatic Storage Manager (ASM)	Yes	No	Yes	No
ASM Cluster File System (ACFS)	No	No	Partially (11.2.0.3+)	Yes
Oracle Cluster File System (OCFS2)	Yes (1.4.1+)	Yes (1.4.1+)	Yes (1.4.1+)	Yes (1.4.1+)
Red Hat Global File System (GFS)	No (11g+)	No (11g+)	No (11g+)	No (11g+)
NFS (Certified only)	Yes	Yes	Yes	Yes
Local Storage	No	Yes	No	Yes

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Check out RAC Technologies Matrix for Linux platforms

http://www.dadbm.com/oracle-11g-rac-database-on-asm-acfs-or-ocfs2/

Http://www.serkey.com/oracle-11g-r2-rac-on-vmware-ocfs2-problem-bfqbk7.html

Oracle 11g RAC database on ASM, ACFS or OCFS2