Edit and correction to my last message to "kidsister":
Correction for iOS device: Settings > iCloud > Storage Area > Manage Storage
Your backups reside in Manage Storage. You can delete your iOS backups there.
I am very sorry for people who still can not do iCloud backups even after changing to Google DNS servers.
But I am very happy to announce that today, I did another 2 successful manual and 2 automatic
iCloud backups in a row in 4 consecutive days for my iPhone and iPad !!! 😉
Google DNS fix works, for me. !!! (By the way, this Google DNS fix does not only works for me,
it also works for 2 more person. Google DNS fix already works for total 3 person (including
original poster of this fix), on this thread.
I was also suffering 🙂, not being able to do automatic or manual iCloud backups, before
I did change my default ISP assigned DNS numbers to Google Public DNS numbers.
For people that Google DNS fix not working:
I am just guessing that: May be just may be, your local ISP (Internet Service Provider) has some
thing to do with this issue. May be there is too much iCloud backups requests are coming to your
ISP, and may be your ISP throttling the speed of your iOS device's access to iCloud backup servers.
So that your connection to iCloud backup server, time-out after some time, and your backup fails.
You may ask me now:
How come you do successful iCloud backups after you changed your
ISP assigned default DNS servers to Google DNS servers (8.8.8.8, 8.8.4.4) ?
Well, some ISPs (depending on your location), can also block access to
iCloud backup servers, even though you changed your default ISP DNS
servers to Google DNS servers. It is a possibility. As I said, I am just guessing.
In my case: My local ISP (Internet Service Provider) is obviously allowing access to
iCloud backup servers while using Google DNS servers on my iPhone or iPad.
P.S.
As, I said before, I may be totally wrong about my guess about, why iCloud
backups do not work for you. It may help, if you contact your ISP helpdesk,
and ask about this issue.