VERITAS File System 4.1 Administrator's Guide

Application Interface
Cache Advisories
Chapter 4 79
The VX_RANDOM advisory indicates that the file is being accessed randomly. For reads, this
disables read-ahead. For writes, this disables the flush-behind. The data is flushed at a rate
based on memory contention.
If VX_NOREUSE is set when doing sequential I/O, buffers are also freed when they are
flushed to disk.The VX_NOREUSE advisory is used as a modifier. If both VX_RANDOM and
VX_NOREUSE are set, VxFS notifies the operating system that the buffers are free and may be
reclaimed. If VX_NOREUSE is set when doing sequential I/O, buffers are also freed when they
are flushed to disk. The VX_NOREUSE advisory may slow down access to the file, but it can
reduce the cached data held by the system. This can allow more data to be cached for other
files and may speed up those accesses.