Apache HTTP Server Version 2.0
Apache uses the
sendfile syscall on platforms
where it is available in order to speed sending of responses.
Unfortunately, on some systems, Apache will detect the presence of
sendfile at compile-time, even when it does not work
properly. This happens most frequently when using network or
other non-standard file-system.
Symptoms of this problem include the above message in the error
log and zero-length responses to non-zero-sized files. The
problem generally occurs only for static files, since dynamic
content usually does not make use of