先不考慮更新後可能會發生的問題, 導入APFS之後的 iOS 其實 ota 更新已經幾乎不可能會死機, 更新步驟可參考國外論壇的描述:
The way the updates work is:
- The OS partition is cloned. (copy on write, this doesn't take extra space) - The update is applied to the cloned partition. (Preparing update) - The partition is verified; every file in it gets an md5 check to make sure the update has no errors. This is why that damn progress bar takes so long. - The system is rebooted from the clone. - Only after the system comes up correctly and various checks pass (the second progress bar) is the previous OS partition deleted.