Veritas File System 5.0 AdministratorÆs Guide, HP-UX 11i v3, First Edition, May 2008

functionality is available in the Veritas File System Dynamic Storage Tiering

(DST) feature.

■ Placing the VxFS intent log on its own volume to minimize disk head movement

and thereby increase performance. This functionality can be used to migrate

from the Veritas QuickLog™ feature.

■ Separating Storage Checkpoints so that data allocated to a Storage Checkpoint

is isolated from the rest of the file system.

■ Separating metadata from file data.

■ Encapsulating volumes so that a volume appears in the file system as a file.

This is particularly useful for databases that are running on raw volumes.

■ Guaranteeing the availability of some volumes even when others are

unavailable.

To use the multi-volume file system features, Veritas Volume Manager must be

installed and the volume set feature must be accessible.

Volume availability

MVS guarantees the availability of some volumes even when others are unavailable.

This allows you to mount a multi-volume file system even if one or more

component dataonly volumes are missing.

The volumes are separated by whether metadata is allowed on the volume. An

I/O error on a dataonly volume does not affect access to any other volumes. All

VxFS operations that do not access the missing dataonly volume function

normally.

Some VxFS operations that do not access the missing dataonly volume and

function normally include the following:

■ Mounting the multi-volume file system, regardless if the file system is read-only

or read/write.

■ Kernel operations.

■ Performing a fsck replay. Logged writes are converted to normal writes if the

corresponding volume is dataonly.

■ Performing a full fsck.

■ Using all other commands that do not access data on a missing volume.

Some operations that could fail if a dataonly volume is missing include:

■ Reading or writing file data if the file's data extents were allocated from the

missing dataonly volume.

115Multi-volume file systems

Features implemented using multi-volume support