Google’s cloud-storage service, Google Drive, went down early Monday morning, and returned about two hours later.

Officially, Google Drive went down as of 7:17 AM Pacific time, according to Google’s status page. At 9:35 AM PT, Google said it had been resolved. During the outage, however, the other services within the Google Apps cloud – including Gmail, Calendar, Google Talk, and Google Documents remained online.

So far, Google hasn’t provided an explanation, but has acknowledged the problem. “We’re aware of a problem with Google Drive affecting a significant subset of users,” Google posted at 8:10 AM PT. “The affected users are unable to access Google Drive. We will provide an update by 3/18/13 9:10 AM detailing when we expect to resolve the problem. Please note that this resolution time is an estimate and may change.”

Update 9:19 AM PT: Google looks like it’s on its way to fixing the problem. “Google Drive service has already been restored for some users, and we expect a resolution for all users within the next 1 hours., it added at 8:55 AM. “Please note this time frame is an estimate and may change.”

Update 9:49 AM PT: “The problem with Google Drive should be resolved,” Google said. “We apologize for the inconvenience and thank you for your patience and continued support.”

What this meant for users is that if you wanted to create a new document or spreadsheet, you can – you must simply save it to your own computer for offline editing. Unfortunately, that requires a user to have previously enabled offline editing.

Google-formatted documents couldn’t be saved to Google Drive, and if you have a document saved on Drive that you or others wish to edit, you’re out of luck. Naturally, other files stored on Drive weren’t accessible. However, photos backed up automatically with Google’s Google+ service were accessible. It’s just part of the complex interdependencies within Google’s cloud services, and what happens when one service goes down while the others stay alive.

Clouds Fail

Although we often talk about the cloud in idealized terms, the fact is that cloud services do fail, and when they do, they often fail in a very high-profile manner. The world’s largest cloud service, Facebook, stumbled in early January, and last week, Microsoft suffered an outage to and its complementary service, which last week it blamed on an overheating datacenter. In 2011, RIM’s BlackBerry email service was down for days, and outages at Amazon’s cloud services have taken down customers including Netflix and others. (Of course, it’s also true that in-house services also fail, they just tend to make fewer headlines.)

Now that Google solves the problem and restores service for its users, we’ll be forced to wait until Google discovers the root cause of the outage, and hopefully, publishes it. But the outage is yet another reminder that no one service is bulletproof, even for a company with the scale and knowledge of Google.

Image courtesy of Shutterstock.