For some reasons, I haven't made full use of my 40GB Apple TV in the last 2 years. Recently, I have more spare time to do so, and would like to use it in my living room with my wide screen TV to enjoy its functionality fully. It works fine to playback all the files I throw at it, but 40GB is too confining for all my photos and music, not to mention my movies and other video collection. To solve this problem, once I have to make my Mac Pro and iTunes running to stream all my data to the Apple TV. It seems a bit troublesome, I dislike it. So I look for a solution to expand the capacity of my Apple TV. Via Google, I've found some useful articles talking about this issue, and I followed them, and finally successfully upgrade the hard drive of the Apple TV lately. Here I'd like to document my process below, but before that, I'd like to show my gratitude to people who I've got useful info from their articles, even though I can not remember their exactly names now.
In summary, the process is relatively simple, a small 40GB hard drive can be freely replaced, thus becomes a DIY Apple TV.
Dismantle the Apple TV, remove the hard drive, and connect it to an Intel Mac Pro via WiebeTech Forensic DriveDock or other 2.5-inch hard drive FireWire bridge. Start the Mac, and you will see that hard drive partition of Apple TV is structured as follows:
/dev/disk5
#: type name size identifier
0: GUID_partition_scheme *37.3 GB disk5
1: EFI 34.0 MB disk5s1
2: 400.0 MB disk5s2
3: Apple_HFS OSBoot 900.0 MB disk5s3
4: Apple_HFS Media 36.0 GB disk5s4
400MB of space which could be used to store the system restore data. Extract overall image via CopyCatX, and recover them to a new hard drive which you want to change back. I found lots of people like using a Western Digital 120GB WD1200VE hard drive. Install the new hard drive to Apple TV, and in the test, you will find the system continues to recognize only 40GB of space, because the partition information is the same with the original 40GB hard drive. But in fact, there are more than 70GB of space not being used.
Remove the new hard drive to re-connect to the Mac, and allocate the unused more than 70GB space to the Media partition with the help of iPartition or other partitioning software. Be careful, not to change the EFI or the other 400MB partition.
After install it back to the Apple TV, all the 107GB space will be recognized completely, you are done!
Now I'm able to store more photos, movies, music, and television shows on the Apple TV. But when it comes to video playback, Apple TV has strict formats limitation, it caused troubles again, and I have to convert all my videos to Apple TV formats .mp4 and .mov in advance. However, this does not the most important thing I'm concerned, because I have already have a video converter on my Mac Pro, and my most intention is to watch my Blu-ray on it. Fortunately, via Google again, I get an available Blu-ray Ripper for Mac to meet my needs, which is able to run on Mac independently as long as you have an external BD drive. To keep HD quality as well as compress BD size, I usually select HD video as my output option. A great product, I like it. Besides this, it seems there are also another version developed for Windows user, attached this BD ripper here, maybe it's your choice.
Well, by the way, Apple installed Fujitsu hard drives in original, and this could be due to their relatively small power and heat consumption, so when replacing the hard drive, you can also take this factor into account. In addition, the replacement of the hard disk will let you lost product warranty, please proceed with caution.