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iMore Question i have iphone 4s and its total storage capacity is 13.6 GB approx and as far i think ios 7 also has occupied some space to be installed so why doesnt ios 8 uses that memory while installing ? and i have read lot of rumour that ios 8 makes device slow specially iphone 4s so when i feel i did mistake installing ios 8 then is there any process to downgrade to ios 7 agian? if yes what is the safest process? please help
In order to do an OTA upgrade of iOS, you have to have enough free space on your phone to hold the full download, AND additional space as "work space" to do the actual install.
As far as falling back to iOS 7, it’s possible IF Apple is still signing iOS 7.1.2 (hearing anecdotal info that they may still be doing so). If you’re going back to iOS 7.1.2, DO IT QUICKLY.