If I update my iPad 4 to iOS 8 from iOS 6, will the standard Over-The-Air update procedure delete any of my data? I don't have a computer to back it up, so this is important.
Generally, updating OTA (over-the-air) is pretty safe, but it's always advisable to have a backup. Doing an update won't clear anything on the device unless something goes drastically wrong.
In my experience, the larger the jump in OS build, the more risk there is of something going wrong with the update. 9 times out of 10, it goes off without a hitch, but every now and then something else comes in to play that can cause the update to fail.
What I would suggest you do is back up your device to iCloud if possible, plug it in to make sure it has a constant power source and can't run flat, and then reset your settings. Don't worry, resetting your settings won't erase any content, but you will have to set things up again such as your home screen layout and your background. To do this:
- Open "Settings"
- Navigate to and tap "General"
- Scroll to the bottom and tap "Reset"
- Tap "Reset All Settings"
You may be asked for your pin and iCloud password at this point so go ahead and enter it. Remember, you won't lose any saved information!
The reason I recommend this is that sometimes there can be a preference that you've changed that can cause a hiccup, or the settings have corrupted somehow and the update will freak out about it (this happened fairly infrequently when I worked at an AASP). Doing this will make sure there's no residual "fluff" before you do the update.