Your hard drive churns. Every click sets off a spinning beachball. Disk Utility doles out the bad news. When your hard drive's end is near, your best hope is a good backup. Of course it is. But, what if you don't have a backup? Or what if you thought you had a backup and it failed? At this point, someone will say, knowingly: "You should have had redundant backups." Shoulda. Woulda. Coulda. You shoulda, you didn't. So, what now?
Keep calm and consider your situation. The fact is, intentionally or not, you probably do have backups of at least some of your data.
Your email messages
Do you use Webmail or IMAP for your email? If so, then you don't need to worry about your email messages; they're safely stored on a server. When you repair or replace your failing Mac, all you'll need to do is enter the information for your email accounts in your email client, or use a Web browser if you use Webmail, and the messages will download.
Data you've synced with iCloud
Have you used Apple's iCloud to sync your email, calendars, Safari bookmarks, reminders, or notes? If so, don't despair. On the new or repaired computer, go to Apple Menu > System Preferences and choose iCloud. Sign in to your iCloud account and check the relevant categories (Contacts, Safari, Calendars & Reminders). Your information should appear.
Files in the cloud
Do you use Dropbox or Google Docs to make it possible for you to see your documents no matter what computer you use? Students, for instance, may store papers in Dropbox so they can access them through a Web browser at school. Or your business may use Google Docs to make it easy for coworkers to collaborate. These files are just where you left them in the cloud; you simply sign back in to the account.
If you've been using an up-to-date version of Dropbox, it's likely the service has also been backing up your photos automatically whenever you connect a USB camera, iOS device, or memory card (provided that you haven't turned down its request to do this). Download a copy of Dropbox's mobile app to your iPhone, iPad, or other mobile device and check.
Your iTunes purchases
If most of your music was purchased through iTunes, it's easy to restore your library. First, make sure that you're signed into iTunes with the account you used to purchase your media. Now click on the iTunes Store button in the top-right of the iTunes window, and click the Purchased link that appears below on the right side. In the resulting screen, click the Music tab and then the All Songs entry. All the music you've purchased will appear in a list. Click the Download All button to download all your past music purchases. You can also redownload purchased movies, TV shows, TV seasons, and books using this same technique.
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