Apache and Samba / CIFS
Looks like apache can have a problem reading from data on a samba mount-points.
The problem I was having was that data was being truncated:
user@host:~$ curl -O http://example.org/path/to/largish_file % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 11 97127 11 11343 0 0 1447k 0 --:--:-- --:--:-- --:--:-- 8484k curl: (18) transfer closed with 85784 bytes remaining to read
While the same apache was returning full versions of files that were not on the samba mount-point.
I noticed this forum comment: http://forums.devshed.com/bsd-help-31/apache-can-t-read-samba-shares-147029.html#post844159
I didn't need to use disable EnableMMAP - this configuration change was all I needed:
The manual (http://httpd.apache.org/docs/2.0/mod/core.html#enablesendfile) indicates that this option (when enabled) means that apache can pass data transfer of static files direct from the kernel to the client without having the data go through apache. In this case it seems that this access fails and having apache read the data itself is a way around the problem.