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

Application Interface
Extent Information
Chapter 466
With very large files, use of space reservation can avoid the need to use indirect extents. It can also improve
performance and reduce fragmentation by guaranteeing that the file consists of large contiguous extents.
Sometimes when critical file systems run out of space, cron jobs, mail, or printer requests fail. These
failures are harder to track if the logs kept by the application cannot be written due to a lack of space on the
file system.
By reserving space for key log files, the logs will not fail when the system runs out of space. Process
accounting files can also have space reserved so accounting records will not be lost if the file system runs
out of space. In addition, by using the VX_NOEXTEND flag for log files, the maximum size of these files can
be limited. This can prevent a runaway failure in one component of the system from filling the file system
with error messages and causing other failures. If the VX_NOEXTEND flag is used for log files, the logs
should be cleaned up before they reach the size limit in order to avoid losing information.