iOS 5 has brought about a host of new features for iPhone, iPod touch and iPad users, but it could have the potential to cause some users and developers a bit of a headache in the way it goes about cleaning house. Marco Arment, the creator of Instapaper, blogged about iOS 5’s cache clearing problem which might cause an issue in the future.
One of the ways that iOS 5 does its housekeeping is that it apparently periodically deletes everything in its “Caches” and “tmp” directory, which as the name implies is used for storing temporary files, such as maps or documents or webpages which can be used for offline viewing. For example users who roam, may choose to preload a map of an area in a foreign country before arriving in order to avoid data roaming charges.
By periodically clearing up these files, users may arrive at their destination without internet or cellphone signal and find themselves unable to view the maps that they have preloaded before. Not to worry though, as this has been reported to only occur when your iOS device is reaching its maximum storage capacity (although what that limit is remains unknown) in order to reclaim memory. Since iOS 5 can’t go about deleting permanent files, such as your songs, videos or apps, it goes to the “Caches” and “tmp” folder and deletes what it considers to be temporary files.
As we said earlier, this could cause quite a few problems, inconvenience being one of them, additional data usage could be another, and there could be a problem with content which cannot be re-downloaded, possibly due to lack of internet or system preferences. While this technically isn’t a bug per se, it’s still an issue that perhaps Apple should consider addressing for the sake of their users and developers.