Veritas 5.0 Installation Guide, HP-UX 11i v3, First Edition, May 2008

VxFS reduces system failure recovery time by tracking file system activity in the VxFS intent
log. This feature records pending changes to the file system structure in a circular intent log.
• Access Control Lists (ACLs)
An Access Control List (ACL) stores a series of entries that identify specific users or groups,
and their access privileges for a directory or file.
• Online Administration
A VxFS file system can be defragmented and resized while it remains online and available
to users. The online administrations operations supported are backup, resizing, and
defragmentation.
• File Snapshot
VxFS provides online data backup using the snapshot feature. An image of a mounted file
system instantly becomes an exact read-only copy of the file system at a specific point in
time. The original file system is called the snapped file system and the copy is called the
snapshot.
• Expanded Application Interface
VxFS supports the following specific features for commercial applications:
— Pre-allocates space for files
— Specifies fixed extent size for files
— Bypasses the system buffer cache for file I/O.
— Specifies the expected access pattern for a file.
• 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 v3. For
more information on files and file system sizes supported by VxFS, see the white paper
Supported File and File System Sizes at http://docs.hp.com.
• 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.
Veritas File System (VxFS) 19