I just deployed a grails web application on a linux machine that also acts as a firewall to the network.
we used the apache tomcat web server to run the web-app, but it does seem to have some problems with the searchable plugin. running on my machine, everything seems to work fine but when I tried to deploy it on the firewall server, it gave me a message that it does not have the permissions to create necessary directories.
I'm sorry I can't display the actual error message but basically I believe it does not have permission to create directories and I am not really what do I have to give permission to so the grails application could do its thing.
This is described in the docs ( http://grails.org/plugin/searchable ) - see http://grails.org/Searchable+Plugin+-+Configuration. If the default location doesn't work for you, run the install-searchable-config script and set the compassConnection property to one that does.