Veritas File System 5.1 SP1 Administrator"s Guide (5900-1499, April 2011)
Treating regular VxFS files as raw devices has the following advantages for
databases:
■ Commercial database servers such as Oracle Server can issue kernel supported
asynchronous I/O calls (through the asyncdsk or Posix AIO interface) on these
pseudo devices but not on regular files.
Cluster file systems
Veritas Storage Foundation Cluster File System (SFCFS) allows clustered severs
to mount and use a file system simultaneously as if all applications using the file
system were running on the same server. The Veritas Volume Manager cluster
functionality (CVM) makes logical volumes and raw device applications accessible
through a cluster.
Beginning with SFCFS 5.0, SFCFS uses a symmetric architecture in which all nodes
in the cluster can simultaneously function as metadata severs. SFCFS still has
some remnants of the old master/slave or primary/secondary concept. The first
server to mount each cluster file system becomes its primary; all other nodes in
the cluster become secondaries. Applications access the user data in files directly
from the server on which they are running. Each SFCFS node has its own intent
log. File system operations, such as allocating or deleting files, can originate from
any node in the cluster.
Installing VxFS and enabling the cluster feature does not create a cluster file
system configuration. HP Serviceguard Storage Management environments require
HP Serviceguard for file system clustering.
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.
Cross-platform data sharing
Cross-platform data sharing (CDS) allows data to be serially shared among
heterogeneous systems where each system has direct access to the physical devices
that hold the data. This feature can be used only in conjunction with Veritas
Volume Manager (VxVM).
See the Veritas Storage Foundation Cross-Platform Data Sharing Administrator's
Guide.
File Change Log
The VxFS File Change Log (FCL) tracks changes to files and directories in a file
system. The File Change Log can be used by applications such as backup products,
Introducing Veritas File System
Veritas File System features
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