IPhone will not back up

Question

Trying to update to iOS4 and it sits for about 30-40 minutes with the "backing up iphone" dialogue box open. The blue bar makes minimal progress and then says "unable to back up. Would you like to proceed w/ update?" I say yes and then nothing.
Have restarted computer and iPhone and tried updating again. No dice.
Help.
Many thanks.
Frank

Answer 1

I HAVE FIXED IT.
I was having this problem something SUPER awful. Like, 3 hour backups that would freeze at 5/6 of the way and not complete. I have a couple fixes for you.
1. Clear out your camera roll. Import all your existing camera roll photos to iPhoto, then delete them off your phone. I had almost 900 photos on my phone.
2. When you first plugged in your iPhone, you had some prompts you probably breezed through. One being a crash report prompt. I will include a guide on how to reverse that damage below.
3. APPS!! The App Store on your phone is still buggy and unstable. Your apps are clogging your backups. Guide also to follow.
If you follow these guides to a T, the process will take you several hours. It took me about a whole day to fix it, but once you do, your backups will be significantly short. Like, where mine used to take 4 hours before halting entirely and not completing, they now take 30 seconds. Hooray!
2."I've seen many posts about backups taking no time at all, and some saying they are taking a long time. I know why some are fast and some are not, it's a setting you chose when you first set up your iphone which does not normally pop up again. Here is my step by step guide to undoing what most of you with slow backups did and making your backups take about 90 seconds on average.
That's right, the actual backup only takes 90 seconds (if you haven't installed anything new since your last sync), the thing that's making everyone's backup take an hour plus is that your sending your crash reports to apple everytime you backup and apples servers are so inundated that you're having to wait for the crash reports to upload and it's taking forever. This is an option that you clicked on your very first sync that you will now undo.
Plug your iphone in so it shows up under "devices" on the left side of itunes. If it starts to sync stop it right away by clicking the x (top middle of itunes). Then go to devices click your iphone so the middle window displays the iphone info and uncheck the "automatically sync when this iphone is connected" you'll find it under the summary tab of your iphone if you're not already there.
Then unplug and re-plug your phone back in.
Now when the phone shows up under devices right click on it and a context menu will pop up, go to the bottom of this list and select "reset warnings"
Now click sync and a warning window will pop up which you probably flew by the first time you set up your phone. It is the source of your backup woes. It is the one saying apple would like to get your crash reports. Also it will have checked by default "don't show this warning again" which is why you never got a chance to undo your mistake of clicking yes last time.
UNCHECK the don't show this again, you want to see this warning window everytime you plug your phone in because you'll always want to click "DO NOT ALLOW." If you want to see why the backup takes so long then click the button where it says to show you the reports. I'll bet if your backups are taking a while this folder is just chock full of crash reports. Go ahead and empty it.
Now everytime you plug your phone in just keep selecting DO NOT SEND THE INFO TO APPLE. (please note the window will only show up if there are crash reports to be sent, so if you empty the crash report folder above then you won't see the warning window again until a new report is generated) I'll bet your backups go way faster from now on.
Also note, if you have a butload of new apps that you installed on your last sync the next backup will indeed take several minutes since this is all new data. (Remember itunes does a backup first then an install incase any of the new apps cause a major problem you'll have a backup from before you installed them. But this means the next time you plug your phone in is the first time your backup will include any apps from the last sync). For example if you sync now and you get a 90 second backup but then you install Brain Challenge (an almost 100 meg app) the your next backup will probably go up to 5 or 10 minutes since none of this is in the last backup. But that's still a far cry less than what many of you have been experiencing."
3. "Extraordinary long backups are caused by an error when an app (or apps) was installed or updated, particularly if you have ever installed or updated using the App Store on the device itself rather than iTunes. Even if you were never aware that there was a problem, they can arise and will cause problems with the backup process. Maybe you did have a problem during an update or install. Maybe the update stalled, or the App Store crashed. These issues are very likely what have been causing your long backups and you didn't even know it. During the backup process these errors cause it to drag and pause for a very long time before it gets moving again. From your view, you just see a normal backup that is taking hours, and undoubtedly annoying you to no end. On the inside, iTunes is trying desperately to get past a roadblock that it doesn't know where it came from.
This is how to fix the problem. This is not a quick fix, but it is an effective fix. And it is a FIX, not a band aid. Depending on how many apps you have installed, this can take several hours to complete. You will also lose all game scores and any other data stored in your apps. You will be starting fresh. It is an inconvenience, but in the end, you will be rewarded with quick, efficient backups, the way Apple intended. And you will never have to dread the
iTunes backup again.
The Process:
1. Open iTunes, go to Edit>Preferences>Syncing and remove all previous backups. Also click "Disable automatic syncing for all iPhones and iPods"
2. In your system file structure, locate the backup files for iTunes.
On Windows: C:\Documents and Settings\USERNAME\Application Data\Apple Computer\MobileSync\Backup
On a Mac: Users/YOURACCOUNT/Library/Application Support/MobileSync/Backup
Delete ALL files and folders inside the Backup folder.
3. Plug in iPod. On the Applications tab, uncheck sync apps. iTunes will ask if you want to remove the apps from the iPod, say yes. Click sync. This will remove all apps on your iPod, it will also backup the ipod. This backup will be very fast, and will recreate the backup folders you deleted in step 2.
4. After the sync is complete, if there are any apps left on your ipod, touch and hold the icon until it starts to wiggle, then touch the X to delete the app. Delete all apps left on your ipod. Then sync again.
5. After the sync is complete, disconnect the iPod and do a hard restart by holding down the sleep/power button until the slider appears, slide to power off. Wait 5 seconds and push the power button again and wait for the ipod to boot up.
6. Connect your iPod again. Now begin adding apps back to your ipod one by one. On the Applications tab, click "Sync applications" AND "Selected applications". Make sure all apps are unchecked.
7. Check one app and sync. After the sync is complete, right click on your ipod under Devices in the left column of iTunes. Click "Back Up" and allow the backup to complete.
8. Repeat step 7 for each app you want to install. Keep the previous installed apps checked, just check one more app each time. Be sure to backup after each install. As you add more and more apps, the backup will take longer and longer as the process scans apps for changes. An initial backup can also be long for a particularly large application. However, ONLY the initial backup after you install an app will take a long time. Subsequent backups are very quick. Even these "long" backups are just minutes long, sometimes up to 15 minutes in my experience.
9. When you are finished installing and backing up all apps, go to Edit>Preferences>Syncing and enable automatic syncing for all iPhones and iPods.
10. Unplug and plug your device back in just for kicks. Let it back up and sync. Better?
Notes:
The very first time an application is backed up, all critical data is written to your hard drive. This is why the backups are so long the first time. Afterward, only data changes are written, so backups are much shorter.
Backup times will continue to vary based on how many apps were altered since the last sync. If you've used one app since the last backup, your backup will be very short. If you've used 20 apps, the backup will be longer. But you will be rid of the dreaded hour (or more) long backup, that is a promise.
Now that your apps are installed and backing up correctly, the number one rule is to never, ever install or update apps through the App Store on the iPod. ONLY install and update through iTunes, and backup after every install or update. The App Store on the iPod is still unstable and can cause lock ups, crashes and freezes. And it is the culprit in these long backup times. Avoid it until the bugs are ironed out.
Also, do not be tempted to disable backups using programs or code edits available online. Your backups are crucial in the event of a restore. Backups contain all of your personal data like game scores, notes, icon arrangement, application data, etc. And it's not a matter of if you'll have to restore one day, it's when, and you'll be glad you have a backup when you do."