Veritas File System 5.1 SP1 Administrator"s Guide (5900-1499, April 2011)

DescriptionFile
Contains the free extent maps for each of the allocation units.free extent map
file
Contains quota information in records. Each record contains resources
allocated either per user.
quotas files
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 data blocks changed since the previous backup, not entire files. This
saves times, storage space, and computing resources required to backup large
databases.
Figure C-1 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.
237Disk layout
VxFS Version 4 disk layout