Veritas 4.1 Installation Guide (HP-UX 11i v3, February 2007)

• Extended Mount Options
The extended mount options supported by VxFS include the following:
— Enhanced data integrity modes
— Enhanced performance modes
— Temporary file system modes
— Improved synchronous writes
— Large file sizes
• Large File and File System Sizes
File systems up to 32 TB and files up to 16 TB in size are supported on HP-UX 11i Version
3. See the white paper “Supported File and File System Sizes” available at http://docs.hp.com
for more information on file and file system sizes supported by VxFS.
• Enhanced I/O Performance
VxFS provides enhanced I/O performance by applying an aggressive I/O clustering policy,
integrating with VxVM, and allowing application specific parameters to be set on a per-file
system basis. However, clustering support is not available with the current release.
• Storage Checkpoints
To increase availability, recoverability, and performance, VxFS offers on-disk and online
backup and restore utilities that facilitate frequent and efficient backup of the file system.
Backup and restore applications can leverage the Storage Checkpoint, a disk and I/O-efficient
copying technology for creating periodic frozen images of a file system. Storage Checkpoints
present a view of a file system at a point in time, and subsequently identifies and maintains
copies of the original file system blocks. Instead of using a disk-based mirroring method,
Storage Checkpoints save disk space and significantly reduce I/O overhead by using the
free space pool available to a file system.
• Quotas
VxFS supports quotas, which allocate per-user quotas and limit the use of two principal
resources files and data blocks.
• Multi-Volume Support
The multi-volume support (MVS) feature allows several volumes to be represented by a
single virtual object. All I/O to and from an underlying volume is directed by way of volume
sets.
VxFS 4.1 on HP–UX 11i Version3
See “Veritas File System 4.1 Release Notes” for more information on features supported with VxFS
4.1 on HP-UX 11i Version 3.
Architecture of VxFS
HP-UX supports various file systems. In order for the kernel to be able to access these different
file system types, there is a layer of indirection above them called Virtual File System (VFS).
Without the VFS layer, the kernel would need to know the specifics of each file system type and
maintain distinct code to handle each.
VFS layer allows the kernel to possess a single set of routines which are common to all file system
types. Handling of the specifics of a file system type are passed down to the file system specific
modules. The following sections describe the VxFS file system specific stuctures.
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