How to sync music to your iPod when your library is bigger than your iPod storage space
Learn about the iPod Selection playlist in iTunes.
If you have a large music library that's too big to fit all your songs on iPod, iTunes can create a playlist called "iPod Selection" that only syncs the right amount of songs to your iPod. This can be a helpful way to make sure you have all your favorite songs, even if your entire library isn't synced to iPod.
When you connect an iPod to your computer, this message appears if your music library is bigger than your iPod's hard disk size and automatic updating is turned on:
The iPod "<your iPod's name>" cannot be synced because there is not enough free space to hold all of the items in the iTunes library (<amount of disk space> required, <amount of disk space> available). Would you like iTunes to turn off podcast syncing and choose a selection of songs to sync to this iPod?
If you click Yes, the following message appears:
iTunes has created the playlist "<your iPod's name> Selection" using your music preferences and will sync the iPod "<your iPod's name>" with this playlist every time it is connected.
The iPod Selection playlist appears in iTunes. It is named "<your iPod's name> Selection". For example, In this graphic, the iPod was named "Apple's iPod", and you can see the playlist is named "Apple's iPod Selection."
Note: If you have enabled the option to sync either Movies or TV Shows to your iPod, iTunes will not be able to create this playlist. The following message appears in this case:
The iPod "<your iPod's name>" cannot be synced because there is not enough free space to hold all of the items in the iTunes library (<amount of disk space> required, <amount of disk space> available).
Note that we are not given the option to create this playlist. To resolve this issue, simply click OK to dismiss the message. Then click the Movies and TV Shows tabs and disable the "Sync Movies" and "Sync TV Shows" options, respectively. After clicking Sync, you should be given the option to create this playlist.
You may enable these options after this playlist is created, but you will likely need to remove some songs from the playlist to make enough room for your Movies and TV Shows to sync over.