VERITAS File SystemÖ 3.5 (HP OnlineJFS/JFS3.5) AdministratorÆs Guide (December 2002)

Chapter 1

The VERITAS File System

VERITAS QuickLog

VERITAS QuickLog moves the VxFS intent log from the physical volume containing the file system onto a

separate physical volume. Without QuickLog, the intent log information for VxFS is usually stored near the

beginning of the file system volume. Because other disk operations (inode, data) are issued on the same

volume, the disk heads seek between the log and file system data areas. Using QuickLog eliminates the seek

time between the log and file system data on the same volume, thereby improving system performance.

See “VERITAS QuickLog” on page 87 for details on the VERITAS QuickLog feature.

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 SANPoint Foundation Suite HA to provide a

complete clustering environment.

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. 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.

See The VERITAS SANPoint Foundation Suite Installation and Configuration Guide, included in the

VERITAS SANPoint Foundation Suite product, for more information.