How much iCloud storage will you need?

Apple's iCloud service is just around the corner, and if you plan on using it, you'll want to know whether the freebie 5 gigabytes will be enough, or if you'll need to upgrade to one of Apple's extra paid storage plans.

I got to wondering that same thing ahead of the service's launch, which Apple will only say is coming sometime this fall, especially given the company's claims that the 5GB should be "plenty of room."

For those who need more, Apple's offering three different storage tiers at $20, $40, and $100 per year, which tack on an additional 10GB, 20GB, and 50GB respectively. As someone with multiple iOS devices who squeezes them to their very fullest, I wanted to see where I'd stand. And with a beta version of iCloud up and running for developers to kick the tires on, I did just that.

The long and the short of it is that 5GB appears to be more than enough space for users with numerous iOS devices on one account, however some apps could push you past that limit and even get in the way of backups.

I found that out the hard way with Rdio, a subscription music service with an iPhone and iPad app that's able to store music on your device. Having that app on both devices meant it alone would take up more than 60 percent of my iCloud storage set aside for backups. Worse yet, it meant I couldn't even start an iCloud backup on the second device I wanted to back up without first jumping to one of the paid plans. More on why that's the case, and how I worked around it a little later on.

What counts, what doesn't

As mentioned earlier, I keep my devices filled with apps and content. My iPhone has 164 apps on it right now, and that's a list I've whittled down. My cumulative app library back on iTunes proper? 1,318. The good news is that with Apple's system, it doesn't really matter if you have one or 1,000 extra apps on your phone, because apps don't count against iCloud's limit. Nor do purchased music, books TV shows or photos you've got synced up through the shared Photo Stream Feature. However, some apps with those same types of media content (though not from Apple) can have a bigger storage footprint than others.

The real reason you need storage with iCloud is for its backup service. Something that's entirely optional if you plan on storing device backups on your computer through iTunes, but that provides a good piece of mind and convenience if you plan on using an iOS 5 device without tying it to a Mac or PC running iTunes. That backup service promises to help in the case of an absolute computer and/or device disaster by saving an exact image of it on Apple's servers. Computer or iPhone flies out of a window of a plane at 30,000 feet, only to fall into lava? Your replacement iOS gadget just pulls down the backup of that lost device from Apple's servers like it never happened.

In that sense, iCloud storage is far flung from the idea of dumping your files somewhere as its successor MobileMe offered with its iDisk virtual storage drive. Instead, it's a mix of backing up what you have on each iOS device, as well as making sure what's on device A ends up on B, C, D, etc. and vice versa. Apple adds additional controls to that system, letting you pick which elements you want synced between each device, right down to the application and its data.

What it works out to

The more you've invested in Apple's system with multiple iOS devices, and the more you're actually using them, the more storage you'll need in order to use the backup service. Take for instance the beta version of iOS 5 we have running on an iPhone 4 here in the office. That device, which I've filled with a backup of my iPhone and linked up to an iCloud test account, used up 427.9 megabytes of iCloud's free 5 gigabytes. That means I could have close to a dozen separate backups of that iPhone sitting on Apple's servers free of charge. However, that was only after I had to selectively leave out certain applications from the backup because they were taking up too much space.

In the test, the culprit was Rdio, a music streaming service that lets you store music locally. In this case, it was 1.7GB of music that had been downloaded to the application for playing offline; a very neat and useful feature, but not at the expense of nearly a third of my free storage cap. That same problem was compounded when backing up both the iPhone and iPad, which had Rdio installed with that same massive chunk of storage. And on the iPad, I ran into a similar problem with VLC media player, an app that lets you store massive video files, which were getting backed up too. Not all apps shared that behavior though. Dropbox, Box.net and Spotify, which offer similar local storage for what can end up being big files, kept only their settings data.

iCloud has a separate application data sharing service that lets iOS apps pass along data to one another. However it's limited to just 64KB per app, and meant to do things like sync up what page you were on in an e-book, or match up your high score and progress in Angry Birds so that you can pick up what you were doing on one device, back on another. The end result is that a large number of apps can be re-downloaded from Apple's App Store servers, while the data that saves your spot in a separate set of servers only takes up a few megabytes--if that. With the system backups though, Apple can save what can be large chunks of data associated with an application that is not part of that special iCloud storage that syncs between devices.

Here's where I ran into another problem. In backing up both the test iPhone and iPad which were running iOS 5 beta 5 to Apple's iCloud backup service, it went beyond the 5GB threshold. And in trying to back up the second device, I was met with an out of space message that prohibited me from backing anything up.

The good news is that once the backup is on there, you can selectively choose which application storage chunks to turn on and off, but (and this is a big but) you have to get the backup there in the first place to do that. There's no option when trying to start that first backup to make those decisions, short of doing a hunt on your iOS device for apps that may be storage hogs. Like on Google's Android, Apple's provided a storage manager with iOS 5 that breaks down how much space each app is taking up on your device, while providing a way to delete it on the spot.

My solution was to ditch whatever music was stored on Rdio within the app itself, do my backup to iCloud, turn the Rdio app backups off, then switch the Rdio app's download back on. This wasn't a huge inconvenience, but I had to re-download that music to the app once again, and the operation as a whole is not something I'd imagine most people would be able to figure out how to tweak without a little instruction or hand-holding. That differs from the "it just works" tag line vaunted during the service's introduction in June.

One other good bit of news is that existing MobileMe users may have little more wiggle room if they run into similar storage hurdles once iCloud launches. As part of the developer testing period, Apple last weekend launched a transfer tool that lets developers convert their MobileMe accounts into iCloud accounts, grandfathering in the 20GB of storage that was included as part of the MobileMe storage to give those users 25GB leading up to the closure of MobileMe next year. So far Apple's made no such promises to offer the same upgrade to non-developer MobileMe users come the iCloud launch.

With iCloud still in the late development stages, these kinks I experienced could very well be worked out by the time it's launched. Though if my dealings with juggling data on different apps on different iOS devices was emblematic, some users may need to think carefully about what's stored within their data-heavy apps in order to stay within the threshold of free.