If you read my last post, you will see how did I set up the drive on Mac, so that I can access it, even though it will not appear on your system as a mounted drive. If you are now able to access the folders the next step is to set it up as a time machine.
There are crude ways of doing it and then there is a very easy way of doing it. I will list the easy way first but if you want to do it the hard way you can do it. All you have to do is to download the automator script and run it. When it asks for the size of the time capsule, just specify the capacity that you want to use. For instance, if your hard disk is 1 TB and you want to use all of it you can definitely use it. This script will create a file (sparsebundle) on your desktop. You need to copy this file to one of the folders on your network drive. To access these folders go to "Go -> Network" and copy this to any of the folders.
Now, open your time machine preferences and set that particular folder as a time machine. Your system will recognize it and it will be able to back it up over wi-fi. Essentially, you got yourself a time capsule for peanuts.
The hard way:
1) First run this command on your terminal:
defaults write com.apple.systempreferences TMShowUnsupportedNetworkVolumes 1
2) Run these commands:
NW_DISK_SIZE=1000000 (it can be anything, size is in MB though)
hdiutil create -library SPUD -megabytes $NW_DISK_SIZE -fs HFS+J -type SPARSEBUNDLE -volname "$NW_IMAGE_NAME" "$NW_IMAGE_NAME"
These commands will create a drive in your home folder. The next steps are similar to the easier way of doing this. Hope this will come handy. This is the way to get a cheap Time Capsule as these drives are available on Amazon for dirt cheap such as Seagate Maxtor Central Axis 1 TB Network Storage Server STM310005CAA00G-RK compared to Apple Time Capsule MC343LL/A 1TB Sim DualBand.