My iPhone's system data has grown extremely large and is using most of the available storage, so I'm planning to erase the phone and set it up again. I've already completed a backup to my computer with iTunes and confirmed that the backup files exist, but I'm worried the backup could be corrupted or fail during restoration. Is there anything else I should do first, such as making another copy or creating an additional backup?
4 Answers
If the computer backup completed successfully, iTunes normally verifies it afterward, so it should be usable. You can make a second backup for extra peace of mind, but there’s no separate way to fully prove a backup will restore correctly without actually restoring it.
Once the phone is set up again, keep regular backups enabled. Some storage issues can be related to accumulated temporary data, and consistent backups may help the system clear certain files. Backing up daily or whenever you’re on trusted Wi-Fi reduces the risk of losing recent data.
Keeping multiple backup methods is a good general habit. For example, use automatic iCloud backups and occasionally make a wired computer backup. Third-party tools can also export messages or other data separately, though they may require payment.
For additional protection, create a temporary iCloud backup as well. Apple may provide temporary iCloud storage for transferring to a replacement or reset device, and you can also use a paid storage tier if needed. Having both a local and cloud copy is safer than relying on just one.

So if I continue making regular iTunes backups after the reset, should that help prevent the storage problem from returning? I’ve run out of iCloud space and would prefer not to pay for more storage.