Appendix: Disk Layout
The disk layout is the way file system information is stored on disk. On VxFS, six different disk layout versions were created to take advantage of evolving technological developments. The disk layout versions used on VxFS were:
Version 1
|
The Version 1 disk layout is the original VxFS disk layout provided with pre-2.0 versions of VxFS.
|
Not Supported
|
Version 2
|
The Version 2 disk layout supports features such as filesets, dynamic inode allocation, and enhanced security. The Version 2 layout is available with and without quotas support.
|
Not Supported
|
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 one terabyte in size.
|
Not Supported
|
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 two terabytes in size.
|
Supported
|
Version 5
|
Version 5 enables the creation of file system sizes up to 32 terabytes. Files can be a maximum of two terabytes. File systems larger than 2 TB must be created on a VERITAS Volume Manager volume. Version 5 also enables setting up to 1024 access control list (ACL) entries.
|
Supported
|
Version 6
|
The Version 6 disk layout enables features such as multi-volume support, cross-platform data sharing, named data streams, and file change log.
|
Supported
|
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, Version 5, and Version 6 disk layouts can be created and mounted. Version 6 is the default disk layout version.
The vxupgrade command is provided to upgrade an existing VxFS file system to the Version 4, Version 5, or Version 6 disk layout while the file system remains online. You must do an upgrade in steps from older to newer layouts. See the vxupgrade(1M) manual page for details on upgrading VxFS file systems.
The vxfsconvert command is provided to upgrade Version 2 and 3 disk layouts to the Version 4 disk layout while the file system is not mounted. Using vxfsconvert, the file system can be converted to the Version 4 layout while offline, then using vxupgrade, you can convert it to Version 5 while online. See the vxfsconvert(1M) manual page for details on upgrading VxFS disk layouts.
The following additional topics are covered in this appendix:
|
