cbreyne16 Said:
"Storage, backup, and update questions: Hello. I am having trouble getting my phone to complete a backup to iCloud and it’s not allowing me to update my iOS. I have 188 of 200GB used but I keep seeing something that says I can update when my phone finishing retiring from iCloud backup. What do I do?"
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Make More Space:
You likely need to have a certain amount of data just to download the file itself, and proceed with the install (around 33GB).
Large files include unneeded files (i.e. Movies & TV Shows). So, for the time being, remove them, and then add them back after upgrading.
"Other" is files are just take up space, such as caches to remember performance. So, delete the space called "Other"
Perform this: How to Clear "Other" in your iPhone's Storage - Use Backup - User Tip
Perform this: Update your iPhone Using a Computer - User Tip