Wim CoekaertsDirector of Linux EngineeringOracle Corporation

Oracle Cluster Filesystem on Linux

One year Later.

What is a CFS ?

Shared Disk Cluster Filesystem Improve management of data for Oracle Real

Application Clusters (RAC) Customer demand for a CFS to run RAC Open solution on the Operating System side

(Linux) free and open source

OCFS Version 1 Releases

Beta Release August 2002– Open source project (GPL license)

Production October 2002 – Red Hat Advanced Server 2.1 for IA32

Production February 2003– United Linux 1.0 for IA32

Production August 2003– Red Hat Advanced Server 2.1 for IPF/IA64

What did we solve ?

255 raw device limit on Linux Difficult to manage raw disk Single view of data files across all nodes Use of standard OS tools (modified) to handle

backups

What didn’t we solve yet ?

Shared Oracle Home installation Binaries and generic file support on CFS Support for other applications (ISV

applications) Volume management Dynamic resizing of partitions Defragmentation of filesystem Online FSCK

Customer Experiences

Large number of production customers today Easy installation and configuration of CFS IO throughput is equivalent to RAW IO Use of the default OS tools can cause slow

throughput and kernel issues. After a few months more requests for generic

filesystem support

Do’s and Don’ts

Red Hat Advanced Server 2.1 for IA32– Use 2.4.9-e.24 or higher kernel

Buffer cache management

Red Hat Advanced Server 2.1 for IPF– Use 2.4.18-e.37 or better

United Linux 1.0 for IA32– Use Service Pack 2a or better

Do’s and Don’ts (2)

Updated fileutilities from http://oss.oracle.com/projects/ocfs

– Dd, cp, tar, md5sum, cksum, mv– O_direct=yes

Always use the above utilities with the O_DIRECT option for better performance and reliability

Use RMAN if possible

Do’s and Don’ts (3)

Use a large blocksize for IO Avoid small allocations (use 1MB and larger) Separate archive log files from datafiles If possible separate out in separate directories Spread load of files across number of

volumes (don’t use 1 volume for everything)– Having one volume causes IO bottlenecks

Use large autoextend size

Do’s and Don’ts (4)

Use comm_voting=1 in /etc/ocfs.conf Async IO support in OCFS 1.0.9 with specific

kernels (need patch for oracle 9.2.0.4) Mix IA32 and IA64 nodes

– OCFS is compatible between the nodes– Easy move of Oracle between architectures (30

seconds)

Customer story

Amazon implemented OCFS for a system Grant McAlister’s experiences

What is coming next ?

OCFS Version 2– Shared Oracle Home– Binaries and logfiles– Faster non database operations

Other platforms– Port to AMD64 for version 1 in progress– Port to PPC64 for version 1 in progress

AQ&Q U E S T I O N SQ U E S T I O N S

A N S W E R SA N S W E R S

Next Steps….

Recommended sessions– Performance and Scalability of Linux in the Enterprise

Tuesday 11:00 am Jamshed Patel– Improving information Assurance of Linux

Tuesday 5:00 pm Mary Ann Davidson– Visit the DEMOgrounds for a customized architectural

review, see a customized demo with Solutions Factory, or receive a personalized proposal. Visit the DEMOgrounds for more information.

Relevant web sites to visit for more information– http://oss.oracle.com/projects/ocfs

Reminder – please complete the OracleWorld online session survey

Thank you.