Raspberry Pi taking over my home network.

I had a separate small mini-itx board acting as a file server.  I didn't have a good enough power supply attached to it, so it would lock up about once a week. Despite this, it seemed to do a good job until last week.  Suddenly last week the server locked up, and afterwards it appeared that upnp services were gone from my network.  I have no clue why even now.

I had been watching how much running Raspbmc was loading the Raspberry PI I have been using as a media player for over a year now, and it seemed like I could put many more services on this low power device.  Losing upnp services gave me an excuse to try to move everything over to the Raspi.

First thing I did was install COPS, from here: http://blog.slucas.fr/en/oss/calibre-opds-php-server  with some explanation here: http://www.linux-magazine.com/Online/Blogs/Productivity-Sauce/Turn-Raspberry-Pi-into-an-Ebook-Server-with-Calibre  Essentially you load your books into Calibre, storing everything on the file server, then you point the COPs server configuration file to where the Calibre database file is located and this will share all those books to many different book readers on your local network.  I use fbreader on a galaxy tab 2 pad computer to read my books.

To get cops to work I had to load in the php and data base modules with the following commands:

sudo apt-get updatesudo apt-get install php5-gd php5-sqlite

I used a long USB extension cord to connect the hard drives from where they were sitting to a free port on the Raspi.  The hub I used does not feed power back into the Raspi.  Feeding power backwards through the usb port is something you evidently must avoid doing, from what I have read.  This can cause the Poly fuses to trip.  Evidently in newer raspi designs these usb poly fuses have been removed.
Once attached all the drives immediately were mounted and instantly showed up in the XBMC video file menu.  I was able to browse and play all the media I had on these drives right away.  I pointed the COPS server at the calibre database on the drives and it instantly began to work.

The last thing I needed was the transmission file download server.  I had been running it for a while on the mini-itx box and loved how easy it was to manage the downloads from my laptop machine.  It installed with the following command:

sudo apt-get install transmission-daemon

Then I followed this guide to configure it: http://www.computeristas.com/wp/?p=98

I am concerned about running the external HD's all the time so they don't use a lot of power and wear out faster than they should, and I didn't want to write to the SD Card in the Raspi that boots the OS, so I added an 8 GB SD card to the hub, formatted it was an ext4 file system and am having transmission save incomplete files to this drive, then copying the files to a hard drive once it is done.  So now, running just the Raspi and saving to this extra SD card is only drawing about 3 watts, not the 20 watts it was taking before.

You can easily log into the Raspi and run top to watch what is going on and most of the time I see over 40% idle even while watching an HD movie and copying a few GB of files across the network.