Specifically, users who still have iOS 6 installed are experiencing self-starting over-the-air (OTA) downloads for iOS 7 to their devices when connected to AC power, averaging around 1 GB per download and occupying 3.1 GB of storage. While the update does not automatically install itself and requires user authentication, the download does not show up in the storage submenu within settings.
The issue is especially problematic for users with little space on their existing devices, as filled space can cause various problems with file management and device efficiency.
CNET confirmed the behavior on both an iPhone 4 as well as a fourth-generation iPad, both of which were running the latest version of iOS 6 before 7 arrived. For the iPad, the download began within minutes of turning on the device and plugging it into A/C power. When finished on both devices, it accounted for a little more than 3GB of space that was previously available on the device, and did not show up in the storage management settings submenu.Last year, users reported similar behavior with the iOS 6 OTA update occurring for those on iOS 5. Earlier this week, Apple claimed that more than 200 million iOS devices are running iOS 7, making it the fastest software upgrade in history.