READ ME before using the Veritas Storage Foundation™ 5.1 SP1 for Oracle RAC Administrator's Guide (April 2011)

and centralized management to VxFS. Using CFS in an SGeRAC environment provides the following
benefits:
• Increased manageability, including easy creation and expansion of files
Without a file system, you must provide Oracle with fixed-size partitions. With CFS, you can
grow file systems dynamically to meet future requirements.
• Less prone to user error
Raw partitions are not visible and administrators cannot compromise them by mistakenly
putting file systems over the partitions. Nothing exists in Oracle to prevent you from making
such a mistake.
• Data center consistency
If you have raw partitions, you are limited to a RAC-specific backup strategy. CFS enables
you to implement your backup strategy across the data center.
CFS Configuration Differences
The first node to mount a CFS file system as shared becomes the primary node for that file system.
All other nodes are “secondaries” for that file system.
Use the fsclustadm command from any node to view which node is primary and set the CFS
primary node for a specific file system.
Mount the cluster file system individually from each node. The -o cluster option of the mount
command mounts the file system in shared mode, which means you can mount the file system
simultaneously on mount points on multiple nodes.
When using the fsadm utility for online administration functions on VxFS file systems, including
file system resizing, defragmentation, directory reorganization, and querying or changing the
largefiles flag, run fsadm from the primary node. This command fails from secondaries.
CFS Recovery
The vxfsckd daemon is responsible for ensuring file system consistency when a node crashes that
was a primary node for a shared file system. If the local node is a secondary node for a given file
system and a reconfiguration occurs in which this node becomes the primary node, the kernel
requests vxfsckd on the new primary node to initiate a replay of the intent log of the underlying
volume. The vxfsckd daemon forks a special call to fsck that ignores the volume reservation protection
normally respected by fsck and other VxFS utilities. The vxfsckd can check several volumes at once
if the node takes on the primary role for multiple file systems.
After a secondary node crash, no action is required to recover file system integrity. As with any
crash on a file system, internal consistency of application data for applications running at the time
of the crash is the responsibility of the applications.
Coordinating CVM and CFS Configurations
After installing SGeRAC, a VCS cluster attribute (HacliUserLevel) is set to give root the ability to
run commands on remote systems by way of the cluster interconnect. CFS takes advantage of this
mechanism to enable you to perform file system operations requiring the primary node be initiated
on secondary nodes and carried out on the primary node transparently.
If you reset this attribute, be aware of which node is the primary for certain file system operations
and perform those tasks from that node. Unlike a non-RAC environment, you cannot run a sequence
of VxVM and VxFS commands, such as resizing a volume and a file system, on the same node
unless it is both the CVM master and CFS primary node.
About CVM and CFS in an SGeRAC Environment 17