Veritas Storage Foundation 5.0 Cluster File System Administration Guide Extracts for HP Serviceguard Storage Management Suite, Second Edition, May 2008

Technical Overview
Benefits and Applications
Chapter 1
12
Benefits and Applications
The following sections describe CFS benefits and some applications.
Advantages To Using CFS
CFS simplifies or eliminates system administration tasks resulting from hardware
limitations:
• The CFS single file system image administrative model simplifies administration by
allowing all file system management operations, resizing, and reorganization
(defragmentation) to be performed from any node.
• You can create and manage terabyte-sized volumes, so partitioning file systems to fit
within disk limitations is usually not necessary - only extremely large data farms
must be partitioned to accommodate file system addressing limitations. For
maximum supported file system sizes, see Supported File and File System Sizes for
HFS and JFS available at: http://docs.hp.com/en/oshpux11iv3.html#VxFS
• Keeping data consistent across multiple servers is automatic, because all servers in
a CFS cluster have access to cluster-shareable file systems. All cluster nodes have
access to the same data, and all data is accessible by all servers using single server
file system semantics.
• Applications can be allocated to different servers to balance the load or to meet other
operational requirements, because all files can be accessed by all servers. Similarly,
failover becomes more flexible, because it is not constrained by data accessibility.
• The file system recovery portion of failover time in an n-node cluster can be reduced
by a factor of n, by distributing the file systems uniformly across cluster nodes,
because each CFS file system can be on any node in the cluster.
• Enterprise storage arrays are more effective, because all of the storage capacity can
be accessed by all nodes in the cluster, but it can be managed from one source.
• Larger volumes with wider striping improve application I/O load balancing. Not only
is the I/O load of each server spread across storage resources, but with CFS shared
file systems, the loads of all servers are balanced against each other.
• Extending clusters by adding servers is easier because each new server’s storage
configuration does not need to be set up - new servers simply adopt the cluster-wide
volume and file system configuration.
• For the following HP Serviceguard Storage Management Suite CFS for Oracle
bundles, the clusterized Oracle Disk Manager (ODM) feature is available to
applications running in a cluster, enabling file-based database performance to
approach the performance of raw partition-based databases:
— T2776CA, T2777CA, T2796CA, and T2797CA
— T2776CB, T2777CB, T8686CB, T8687CB, T8696CB, and T8697CB