Veritas Storage Foundation 5.0.1 Cluster File System Administrator's Guide Extracts for the HP Serviceguard Storage Management Suite on HP-UX 11i v3

1 Technical Overview
This chapter includes the following topics:
• “Overview of Cluster File System Architecture” (page 9)
• “VxFS Functionality on Cluster File Systems” (page 10)
• “Benefits and Applications” (page 12)
HP Serviceguard Storage Management Suite (SG SMS) bundles provide several options for
clustering and storage. The information in this document applies to the SG SMS bundles that
include the Veritas Storage Foundation™ 5.0.1 Cluster File System and Cluster Volume Manager
by Symantec:
• SG SMS version A.03.00 bundles T2775DB and T2777DB for HP-UX 11i v3
• SG SMS version A.03.00 High Availability Operating Environment (HAOE) bundles T8685DB,
T8686DB, and T8687DB for HP-UX 11i v3
• SG SMS version A.03.00 Data Center Operating Environment (DCOE) bundles T8695DB,
T8696DB, and T8697DB for HP-UX 11i v3
SG SMS bundles that include the Veritas Storage Foundation Cluster File System (CFS) allow
clustered servers running HP-UX 11i to mount and use the same file system simultaneously, as
if all applications using the file system are running on the same server. SG SMS bundles that
include CFS also include the Veritas Storage Foundation Cluster Volume Manager (CVM). CVM
makes logical volumes and raw device applications accessible throughout a cluster.
As SG SMS components, CFS and CVM are integrated with HP Serviceguard to form a highly
available clustered computing environment. SG SMS bundles that include CFS and CVM do not
include the Veritas™ Cluster Server by Symantec (VCS). VCS functions that are required in an
SG SMS environment are performed by Serviceguard. This document focuses on CFS and CVM
administration in an SG SMS environment.
For more information on bundle features, options and applications, see the Application Use Cases
for the HP Serviceguard Storage Management Suite White Paper and the HP Serviceguard Storage
Management Suite Release Notes at:
http://www.docs.hp.com - select “High Availability”, then select “HP Serviceguard Storage
Management Suite”
Overview of Cluster File System Architecture
CFS allows clustered servers to mount and use the same file system simultaneously, as if all
applications using the file system are running on the same server. CVM makes logical volumes
and raw device applications accessible throughout a cluster.
Cluster File System Design
Beginning with version 5.0, and continuing in version 5.0.1, CFS uses a Symmetric architecture
in which all nodes in the cluster can simultaneously function as metadata servers. CFS 5.0 has
some remnants of the master/slave node concept from version 4.1, but this functionality changed
in version 5.0 along with a different naming convention. The first server to mount each cluster
file system becomes the primary CFS node; all other nodes in the cluster are considered secondary
CFS nodes. Applications access user data directly from the node they are running on. Each CFS
node has its own intent log. File system operations, such as allocating or deleting files, can
originate from any node in the cluster.
Overview of Cluster File System Architecture 9