Veritas File System 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

The VERITAS File System
Cluster File Systems
Chapter 1 19
Cluster File Systems
Clustered file systems are an extension of VxFS that support concurrent direct media access from multiple
systems. CFS employs a master/slave protocol. All cluster file systems can read file data directly from a
shared disk. In addition, all systems can write "in-place" file data. Operations that require changes to file
system metadata, such as allocation, creation, and deletion, can only be performed by the single primary file
system node. To maintain file system consistency, secondary nodes must send messages to the primary, and
the primary will perform the operations.
Installing VxFS and enabling the cluster feature does not create a cluster file system configuration. File
system clustering requires other Veritas products to enable communication services and provide storage
resources. These products are packaged with VxFS in the Storage Foundation Cluster File System to provide
a complete clustering environment.
See the Veritas Storage Foundation Cluster File System Installation and Configuration Guide, included in
the Veritas Storage Foundation Cluster File System product, for more information.
To be a cluster mount, a file system must be mounted using the mount -o cluster option. File systems
mounted without the -o cluster option are termed local mounts.
CFS functionality is a separately licensable feature.