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

Extent Attributes
Commands Related to Extent Attributes
Chapter 3 57
Reservation Persistence
A reservation request can ensure that the reservation does not become a persistent attribute of the file. The
unused reservation is discarded when the file is closed.
Including Reservation in the File
A reservation request can make sure the size of the file is adjusted to include the reservation. Normally, the
space of the reservation is not included in the file until an extending write operation requires it. A
reservation that immediately changes the file size can generate large temporary files. Unlike a ftruncate
operation that increases the size of a file, this type of reservation does not perform zeroing of the blocks
included in the file and limits this facility to users with appropriate privileges. The data that appears in the
file may have been previously contained in another file.
Commands Related to Extent Attributes
The VxFS commands for manipulating extent attributes are setext and getext; they allow the user to set
up files with a given set of extent attributes or view any attributes that are already associated with a file. See
the getext (1M) and setext (1M) manual pages for details on using these commands.
The VxFS-specific commands vxdump and vxrestore, and the mv, cp, and cpio commands, preserve
extent attributes when backing up, restoring, moving, or copying files.
Most of these commands include a command line option (-e) for maintaining extent attributes on files. This
option specifies dealing with a VxFS file that has extent attribute information including reserved space, a
fixed extent size, and extent alignment. The extent attribute information may be lost if the destination file
system does not support extent attributes, has a different block size than the source file system, or lacks free
extents appropriate to satisfy the extent attribute requirements.
The -e option takes any of the following keywords as an argument:
warn Issues a warning message if extent attribute information cannot be
maintained (the default)
force Fails the copy if extent attribute information cannot be maintained
ignore Ignores extent attribute information entirely