IPhone Backup Restore Ate 30 GB of HD Space – How to Clean

Coincidentally, that happened to me just one week ago when Wifi sync died en route. The solution is simple, but totally non-intuitive: do the exact opposite of what feels right, and all will be well (not exactly Apple’s finest hour in UI intuitiveness):

1. Choose “set up as new phone” on the initial screen. In the dialog that pop ups give your phone the name it had before (important – if your case is similar to mine, it will be pre-filled). This will re-register the phone with iTunes sync.
2. Your phone will do an initial sync with all sync options (music, movies, ebooks etc.) disabled except apps, which are set to “sync all” (if you have a lot of apps in iTunes you are not usually syncing to your phone, the initial sync will flood your phone with these. Delete them out of iTunes beforehand, or from the iPhone after the initial sync). Apps already on the phone will not be overwritten and won’t lose their settings.
3. At this point, all media will still be both in Tunes and on the phone, but not in a synchronized state. Re-check all your sync settings. Acknowledge the “all media on this phone will be deleted” warning. Don’t fret: as long as you are syncing with the same iTunes library as before, nothing will be deleted in the next step.
4. Trigger a sync manually. iTunes will compare what is on the iPhone and what it is meant to sync, and will not re-transfer media already on your phone. Once done, both media libraries will be in sync again. One gotcha though: make sure the downsample setting on the first option page is set as it was before (i.e. on if you downsample music to 128 Kb/s in sync, off otherwise), or you music will be re-synced because bitrates do not match – quite a pain if you have a large library.

After that, your phone will be back ins sync without undue hassle (i.e. worrying about out of date backups in iTunes, iCloud restore etc.).

Yay! After many attempts I finally restored my iPhone to the state that it was at when I entered the Apple Store. I manually backed up my iPhone to a brand new iTunes library that my iPhone was not being synced to. So to properly restore from back up I needed to restore from a brand new iTunes Library. At first glance, this seems wrong. I saw my iPhone after this initial restore with zero non-Apple applications, so at this point I gave up on this method. But this is expected. To continue, after restoring from a brand new iTunes library then open the iTunes library that the phone was synced to and wait for everything to sync back. Once this process completed I had the correct home screen arrangement and everything, minus the status of the Podcasts that I had listened to, which, with a 1001 item Podcast library saddening me. It only restored unplayed/played status from the last time I synced the device.

Note: The iPhone remembers where the last play point was, if it was in the middle of the podcast, but doesn't show it. (i.e. Podcast Episode X shows its unplayed. I click on it and it starts playing with 3 minutes left) I want to get this information visible again so that I can see what episodes I have played completely through.