Can anyone with experience of implmementing / running a Lucene.NET solution recommend rough system specifications for a live environment. Is it processor, memory or disk intensive. Does it only use a single processor, so having a box with multiprocessors / cores wouldn't return much benefit, etc?
This is for a greenfields development so there is no relevent existing system to base usage from. It is expected that the data we would be indexing would contain 200K documents (customers) and would contain the standard stuff like name, contact details and a couple of addresses - so each record wouldn't be too big.
Helpfully we need to start our hardware recommendations before we really have chance to create any test solution - and the hardware that currently exists would make any tests difficult to compare / draw conclusion from.
You won't get a decent andwer as it totally depends on what you do (number and complexitiy of queries) as well as the size of the storage.
I would question the selectin of Lucene as proper technology here to start with. Seems to be a "the only tool I know of is ah ammer, so I make my problem look like a nail".
Lucene is not a generic database - it is a document full text index search system. it has serious limitations as well as serious strenghts. Any non-document data (address book etc.) I would NOT store in something like lucene.
That said, 200.000 documents sounds like an awfull... mediocre size. You are probably OK with a "decent system". Disc wise my bet always is to use a Velociraptor Raid 10 for data storage if performance becomes an issue, but even then the hard disc controller can make a hugh difference.