Hi Fran,

   I think it will depend a bit on your particular apache setup, however, I was able to set the apache user on our system by specifying the values of for APACHE_RUN_USER and APACHE_RUN_GROUP in the Apache envvars (environment variables) file, (ours resides in /etc/apache2/envvars) as below:

export APACHE_RUN_USER=eprints
export APACHE_RUN_GROUP=eprints

Before making edits to the config, it's probably best to make a backup of the original; you will also likely need to be running as the root user to edit the config. Your config file likely has these variables exported already (most likely as apache/apache or www-data/www-data), so be sure to comment out or replace any existing definitions.

After making the changes, you will have to restart Apache before they take effect. It will also be necessary to revert ownership of the documents directory back to eprints/eprints. In configuring our repository, I found that running apache as eprints and setting blanket ownership within the eprints directories to the eprints user helped to solve essentially all permission issues.

Cheers,
Casey