Google has promised to get the last remaining Gmail accounts up and running soon, after a bug took down the service for thousands yesterday.
Users said that their Gmail accounts were suddenly empty of any messages, but Google promised the emails were safely backed up to tape.
To protect your information from these unusual bugs, we also back it up to tape.
"I know what some of you are thinking: how could this happen if we have multiple copies of your data, in multiple data centres? Well, in some rare instances software bugs can affect several copies of the data," Ben Treynor, vice president for engineering, said on the Google blog.
"That’s what happened here. Some copies of mail were deleted, and we’ve been hard at work over the last 30 hours getting it back for the people affected by this issue."
However, the nature of the bug - in a storage software update - meant Google had to turn to its tape backups.
"To protect your information from these unusual bugs, we also back it up to tape. Since the tapes are offline, they’re protected from such software bugs," Treynor explained.
"But restoring data from them also takes longer than transferring your requests to another data centre, which is why it’s taken us hours to get the email back instead of milliseconds."
Google said the issue affected only 0.02% of Gmail accounts, but warned that email sent to affected inboxes between Sunday night and yesterday afternoon would not have gotten through.