Corrupted backups

One thing that may have caused the crashing issue is that iTunes 7.7.1 seems to have a terrible problem completing backups. An interrupted backup corrupts it, and may lead to undesired corruption also of the DRM checking (just a theory).  Furthermore, the initial backup takes hours to complete, if it completes at all.

Tips for safer backup

  • If you disable automatic backup (see below), you can still do a manual backup by right-clicking your iPhone device in iTunes.*
  • Turn on airplane mode before starting a backup.  If you don’t and you receive a call, the backup will abort and leave you with a corrupted backup.
  • Plug your iPhone into the USB port of the computer directly and do not use a USB hub.
  • Turn off automatic syncing in iTunes Syncing preferences.

* I found that the supposed contextual-menu for the iPhone device manual backup option does not actually exist.  Looking into why, but it would be seriously annoying if the manual option were removed when you disable the automatic option.

Disabling automatic backups

As of now, the automatic backup is completely useless, and it is best to disable it.   Especially if you’re using cracked IPAs with a jailbroken iPhone, it is not advisable to restore from backup anyway, so why bother?

There is a simple application for the Mac called disablebackup that toggles this.

You can also do it directly in Terminal, with iTunes quit:

defaults write com.apple.itunes DeviceBackupsDisabled -bool YES

To turn it back on, issue the reverse command:

defaults write com.apple.itunes DeviceBackupsDisabled -bool NO

Locating or trashing existing backups

iTunes stores backups here on the Mac:

~/Library/Application Support/MobileSync/Backup/

If you delete these, make sure iTunes is quit first.

You can also delete them directly in iTunes’ Synching preferences.

Backup using rsync instead

Instead of using the buggy iTunes to backup your iPhone, you can also do it in a standard UNIX way with the UNIX command “rsync”.  The TwiPhone blog explains how. I would add that you might want to make a shell alias for this.  In bash, you can add a line like this* to  your “.bashrc” file with pico or vi:

alias iphonebkp='rsync --exclude private/var/mobile/Media/iTunes_Control/ -av
root@my_iPhone.local:/ /Volumes/External_Drive/Archives/iPhone-Backup/ --delete'

* These two lines should be a single line separated by a space.  I broke them into two for readability. Of course, replace my_iPhone with your actual iPhone name and specify a proper path to a local Mac archive folder in the second path.

 

from Joy of Tech

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