Storing files on second hard drive

I feel like I missed something as this should all be very simple.

I have a server that is a combination Wordpress/Omeka server. Some of my pdf files are very large, and I need to store them on an external hard drive connected to the server. Which line of which file do I have to tweak so that Omeka will look for my external drive?

I'm using a Debian Linux 8.5 web server, and the site URL for my Omeka collection is

You can configure where Omeka stores and looks for files in application/config/config.ini.

For the regular local filesystem storage, there are two relevant settings:

storage.adapterOptions.localDir sets the local path that Omeka will save the files to.

storage.adapterOptions.webDir sets the base URL that's prepended to the filename for when Omeka needs to generate a URL to a stored file.

You can have the files stored anywhere you want on the filesystem as long as Omeka can write there and you have a web server set up to serve files from that directory.

Neither of the lines you referred to are in my application/config/config.ini file. Are you saying I need to add these lines, or is it possible you're referring to an older version of the software and those lines have been moved to a different folder?

Also, regarding setting the local path, what is the syntax that Omeka prefers? Does it request a single slash or a double slash before "media"?

Should the base URL entry include "http://" at the beginning or is it just "www."?

When you say make sure that Omeka can write to the folder, are you referring to using "chown" to set the owner of that folder to the www-data user, or is there some other process specific to this software that I should know about?

Yes, you would add those lines.

I'm not sure what you mean by your question about the local path, but the setting should just be a regular absolute path, so starting with a single forward slash.

The base URL should be the entire URL, including the http://

You'd make the folder writable by Omeka in whatever method you want and will work with your server's setup. For servers using mod_php, setting the group to one of Apache's groups and adding group-write permissions is one way that works, yes. It's the same process as making the "files" folder writable during installation.