I recommend everyone read this document from Apple: http://support.apple.com/kb/HT1766
Of specific importance is the fact that only one backup – the latest – is stored on your HDD. This means that if you need to restore the backup and you accidently overwrite it, it is no longer useful. Hence, I recommend the following:
- Backup the backup directory. If you have a Mac, then I highly recommend Time Machine. You can use any normal external harddrive to create a cheap, simple, and very effective backup solution. If you are not using Time Machine or a similar solution, the backup the backup directory regularly (the directory is listed in that article, and below).
- If you experience an issue with your iPhone and need to restore the data then DO NOT SYNC OR BACK IT UP until the issue is resolved.
The backup directory for the iPhone data is here:
Mac: ~/Library/Application Support/MobileSync/Backup/
Windows XP: \Documents and Settings\(username)\Application Data\Apple Computer\MobileSync\Backup\
Windows Vista: \Users\(username)\AppData\Roaming\Apple Computer\MobileSync\Backup\
Restoring the backup:
If you need to do a Restore to get your data back, first backup the backup directory (see above).
Then, follow the instructions here to restore: http://support.apple.com/kb/HT1414 basically the steps are, you restore the iPhone, then restore the backup, then sync to get your apps back.
Note that one of the first steps of the restore process asks if you want to back up your data. This is for people who have an issue with their iPhone and are NOT trying to rollback to a previous version of the data. DO NOT select the BACKUP option during the restore, as this will overwrite the very backup you are trying to restore!
