Hi Raj,
a few lines below there is a topic about changing VUM repository. Try this workaround and it could be what you need.
in a few words - change <patchStore> tag(into vci-integrity.xml) content to point the new location/drive and and move the repository there
Another option that is clean and reliable is to reinstall VUM. You can use it also if you don't have a lot of baselines created, settings to change, etc. During the initial VUM installaion there is a screen with option to select location for repository - select 80 GB drive there and you are ready. 80 GB are more than enough
thanks,
petko