Veritas File System 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

Disk Layout
Disk Layout
Appendix C232
The following figure shows how the kernel and utilities build information about the structure of the file
system. The super-block location is in a known location from which the OLT can be located. From the OLT,
the initial extents of the structural inode list can be located along with the inode number of the fileset header
file. The initial inode list extents contain the inode for the fileset header file from which the extents
associated with the fileset header file are obtained.
As an example, when mounting the file system, the kernel needs to access the primary fileset in order to
access its inode list, inode allocation unit, quotas file and so on. The required information is obtained by
accessing the fileset header file from which the kernel can locate the appropriate entry in the file and access
the required information.
The Version 4 disk layout supports Access Control Lists and Block-Level Incremental (BLI) Backup. BLI
Backup is a backup method that stores and retrieves only the datablocks changed since the previous backup,
not entire files. This saves times, storage space, and computing resources required to backup large databases.
This file system technology is implemented in other VERITAS products. For information on how to use this
feature, contact your sales channel.