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http://www.synology.com/enu/products/DS409slim/index.php4-bay NAS, tiny device, low power consumption, probably the best home NAS OS there is, oodles of networking and server stuff built-in (web server, mail server, IP camera interface...) as well as all forms of RAID and hybrid RAID which handles volume expansion easily while maximising space with multiple disks of different sizes, much more capable than WHS.
Built-in DLNA server that works but is a bit naff as its customisation options are basically non-existent - can only index music by genre/track artist/album/title/date/folder. Photo and video indexing is only by date and folder. Also runs Squeeze Server and I believe Twonky as well, but these are much more complex to set up than JRiver MC and nowhere near as flexible.
Imagine loading it with SSDs...
Lovely little home server device that could just sit there, silent, consuming little power, serving your content directory as you want it catalogued, across your entire network transparently to renderers and controllers.
Sticking point. It's Linux!
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