Just like a hard drive, you do not get the full 30gb of space. Some is lost due to the conversion. A byte is 1024 bits, etc, etc.
In addition, there is an operating system that is needed. All of that takes up some space. So 28.5 gb of space is pretty much exactly what to expect. Nothing wrong there.
Some is lost due to the conversion. A byte is 1024 bits, etc, etc. Just for clarification, there is nothing lost at all due to any conversion. The discrepancy exists merely because of a difference in the way a gigabyte is measured by hard drive manufacturers and how it is reported by the operating system.
8bits=1byte
1024 bytes=1kb
1024kb=1mb
1024mb=1gb....turns out 30gb isn't really 30,000,000,000 bytes and your iPod doesn't really hold 30gb in a practical sense