iPhone: How to ensure iBook files are stored locally There was a bug in iBooks. When file storage capacity is low, iOS deletes some iBooks files. The bug was that it deleted many files even if storage capacity was ok.

And I lost a bunch of PDF stored locally on my iPhone.

Today I synced again a few PDFs from Mac iBook  →  iPhone iBook.

Have two questions


how to check reliably that files are stored locally on iPhone (ie not iCloud)? I mean, I could use the airplane mode and see if files are still openable ... but maybe there is a cache or something.
actually, how to reliably use only local files - and get rid of iCloud access, at least for iBooks [ iCloud is off on my iPhone for iBooks, but files disappeared anyway ]?
Related question: Books automatically deletes my books when offline, and when there is enough space on device


  how to check reliably that files are stored locally on iPhone (ie not iCloud)? I mean, I could use the airplane mode and see if files are still openable ... but maybe there is a cache or something


If you are on iOS 12, then go to library and next to the book at the bottom-left there will be a cloud symbol if it is stored in iCloud and no cloud symbol if it isn’t.


  actually, how to reliably use only local files - and get rid of iCloud access, at least for iBooks [ iCloud is off on my iPhone for iBooks, but files disappeared anyway ]?


Got to Settings -> [your name] -> iCloud and make sure Books is turned off.

Note: make sure you download all your Books before turning it off.