to those of you who haven't updated their iPhone or iPad to iOS 8 and are using iCloud to backup their files: we would like to suggest you hold off on updating to iCloud Drive until Apple fixes the problems with it.
iCloud Drive is basically a Dropbox version of the old iCloud Documents, with a greatly changed architecture, causing devices with iCloud Drive to be incompatible with devices with iCloud Documents when it comes to syncing. This means you won't be able to sync with your Mac, for example, because iCloud Drive won't be available there for a while. We've also heard multiple users being unable to find their collection files in iCloud Drive, and there is simply not much we can do on our side.
If you want to upgrade to iCloud Drive, I'd suggest saving your files in Dropbox first, so you can at least pull the files from there if iCloud Drive messes things up.
Decked Builder Support