It is well known to developers that sendfile() will fail under various circumstances, often involving non-standard filesystems like nfs or smb. Unfortunately, this is not well-known to users. I've added it to the FAQ: http://httpd.apache.org/docs-2.0/faq/error.html#error.sendfile but it would certainly be better to help our users out a little more.
Is there any way to: 1. Flag this error and mention EnableSendFile in the error log message. 2. Log an error, but fall back to the non-sendfile handling of files so that at least the file still gets delivered. Or perhaps it would be better to have EnableSendfile off by default and recommend it as a performance enhancement. Sorry, I have no desire to dig into this code, but it is a common source of confused users, so it would be nice to improve this. Joshua.
