VERITAS File SystemÖ 3.5 (HP OnlineJFS/JFS3.5) AdministratorÆs Guide (December 2002)

Appendix C
143
C Disk Layout
Introduction
The disk layout is the way file system information is stored on disk. On VxFS, five different disk layout
versions were created to take advantage of evolving technological developments. The disk layout versions
used on VxFS were:
Some of the disk layout versions were not supported on all UNIX operating systems. Version 2 and 3 file
systems can still be mounted, but this will be disallowed in future releases. Currently, the Version 4 disk
layout can be both created and mounted.
The vxupgrade command is provided to upgrade an existing VxFS file system to the Version 4 layout while
the file system remains online. See the vxupgrade (1M) manual page for details on upgrading VxFS file
systems.
The vxfsconvert command is provided to upgrade older VxFS disk layout version to the Version 4 layout
while the file system is not mounted. See the vxfsconver (1M) manual page for details on upgrading VxFS disk
layouts.
The following additional topics are covered in this appendix: Disk Space Allocation The VxFS Version 4 Disk
Layout:
• Disk Space Allocation
• The VxFS Version 4 Disk Layout
Version 1 The Version 1 disk layout is the original VxFS disk layout provided with pre-2.0
versions of VxFS.
Version 2 The Version 2 disk layout was designed to support features such as filesets, dynamic
inode allocation, and enhanced security. The Version 2 layout is available with and
without quotas support.
Version 3 The Version 3 disk layout encompasses all file system structural information in files,
rather than at fixed locations on disk, allowing for greater scalability. Version 3
supports files and file systems up to in size.
Version 4 The Version 4 disk layout encompasses all file system structural information in files,
rather than at fixed locations on disk, allowing for greater scalability. Version 4
supports files and file systems up to in size.