DATA Location

Is it possible (and how) to implement a data path on another partition (linux) for an existing system? And then if I do
notgain anything, merging it to the production /data path? 

Scenario of what I want to achieve (/mnt/data is already running)

    /mnt/data    resides on an NFS share
                Contains over 2 Billion web sites crawled (yeah another search-engine site)

want to add:

    /opt/data        resides on internal drive
                Will contain keyword hash system

Then if I find this does not improve anything - or runs tight (running on IBM Blade center with 76gb internals - so I
maybe limited), that I can simple shutdown postgres, scp /opt/data/folder/ to the NFS - bring up postgres - fix any
conffile, and everything is on the multi-terabyte array? 

Checking the pulse of all you speed freaks that just hit the floor because this is on NFS not iSCSI -- don't worry,
whenthis site goes live it will be iSCSI. We have been in private development for 3 years... and the NFS still out runs
theInternet connections.