About disk layouts

The disk layout is the way file system information is stored on disk. On VxFS, several different disk layout versions were created to take advantage of evolving technological developments.

The disk layout versions used on VxFS are:

Version 1

Version 1 disk layout is the original VxFS disk layout provided with pre-2.0 versions of VxFS.

Not Supported

Version 2

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

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

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 one terabyte in size.

Not Supported

Version 5

Version 5 enables the creation of file system sizes up to 32 terabytes. File sizes can be a maximum of 4 billion file system blocks. File systems larger than 1TB must be created on a Veritas Volume Manager volume.

Not Supported

Version 6

Version 6 disk layout enables features such as multi-volume support, cross-platform data sharing, named data streams, and File Change Log.

A disk layout Version 6 file system can still be mounted, but this will be disallowed in future releases. Symantec recommends that you upgrade from Version 6 to the latest default disk layout version. In this release, disk layout Version 6 cannot be cluster mounted. You cannot create new file systems with disk layout Version 6. The only operation that you can perform on a file system with disk layout Version 6 is to upgrade the disk layout to a supported version. If you upgrade a file system from disk layout Version 6 to a later version, once the upgrade operation finishes, you must unmount the file system cleanly, then re-mount the file system.

Deprecated

Version 7

Version 7 disk layout enables support for variable and large size history log records, more than 2048 volumes, large directory hash, and SmartTier.

Supported

Version 8

Version 8 disk layout enables support for file-level snapshots.

Supported

Version 9

Version 9 disk layout enables support for file compression, file replication, and data deduplication.

Supported

Some of the disk layout versions were not supported on all UNIX operating systems. Currently, only the Version 7, 8, and 9 disk layouts can be created and mounted. The Version 6 disk layout can be mounted, but only for upgrading to a supported version. Disk layout Version 6 cannot be cluster mounted. To cluster mount such a file system, you must first mount the file system on one node and then upgrade to a supported disk layout version using the vxupgrade command. No other versions can be created or mounted. Version 9 is the default disk layout version.

The vxupgrade command is provided to upgrade an existing VxFS file system to the Version 7 layout while the file system remains online.

See the vxupgrade(1M) manual page.

The vxfsconvert command is provided to upgrade ext2 and ext3 file systems to the Version 7 disk layout while the file system is not mounted.

See the vxfsconvert(1M) manual page.