Cannot sync to old nano when transferred to new computer.

I recently transferred all my music from an old computer to a new laptop, using the Home Sharing option. This was after I tried using another method, which was given on the Apple support page for transferring the music. When I looked at the music on the laptop, only 117 of 844 were there. So, I used the Home Sharing option. I now have all the music on the laptop, but when I went to sync it to the nano, I received the message that I couldn't sync it, because I needed an additional 2.7 GB of space. All the music in the iTunes library came from the nano, so I don't know why this occurred.

Should I reinitialize the nano and attempt to sync again, or is there another option?

Thanks!