Articles: Disk Utility & Recovery Mode
Every week I get a tech support call at PowerMax that requires the customer to boot into Recovery Mode or utilize Disk Utility. Both are amazing tools Apple provides free to those of us using OS X. As long as you’re running Lion (10.7) or above, you can boot into Recovery Mode with just an internet connection.
Disk Utility is located right in your Utilities folder (Applications > Utilities > Disk Utility). If you’re experiencing trouble with your machine, like it’s running slowly or other strange things are happening, one of the first things you can try is to check your hard drive. From Disk Utility, you can perform a “Live Verification” on your (Mac OS Extended (Journaled)-formatted) HD using “Verify Disk” while running the OS from that same disk! If it needs to be repaired, your Mac will tell you so, and then you would use the “Repair Disk” option. Note: it will likely be grayed out until your Mac tells you to repair it.
Sometimes, after many installs and deletions and upgrades, the permissions to certain files deep within your Mac get all screwy. They no longer match with where they’re supposed to go. This can cause all sorts of problems, so when you use Disk Utility to “repair disk permissions,” you’re telling your Mac to look deeper and make sure everything matches up.
Both of these options are under the “First Aid” tab. Although this can fix some problems caused by a major install or deletion of files or applications, it’s not something to run frequently. After you’ve tried the reset the PRAM and SMC, then you might try to run Disk Utility, but use it as a last resort before you call for tech help or take your machine in for diagnostics.
The “Erase” tab is fairly self-explanatory, but beware! You can’t undo an erase! Once that data is gone, it’s gone forever. Use with extreme caution. Same with the RAID tab, something I won’t go into here. The last is the “Restore” tab, and this is a little confusing. It doesn’t really restore anything, but it rather makes a copy of data from one disk onto another. If you’re using Time Machine (and I really hope you are), you probably won’t need this too much.
Please backup everything before you start messing with your Mac. Also, do your research or call for professional help.
From Recovery Mode, you can do so many things. You can reinstall your operating system (OS) back to the version with which it came. You can erase your startup drive completely and do a fresh OS install. You can restore your Mac from a Time Machine backup. You can verify and repair your hard drive using Disk Utility, as above, but on a deeper level because you’re not actually running the OS from your internal HD.
Getting into Recovery Mode is so easy to do. Just restart your Mac and hold down the Command and R keys until you see the Apple logo. Instead of your desktop, you will see this:
If your normal desktop or a login window appears instead, you probably didn’t hold down Command + R long enough. Just restart and try again! It’s that simple!
PARTITION, ERASE, INSTALL OS
If you need to partition or erase your hard drive, you would do so from the Disk Utility in Recovery Mode. This is also the place to reinstall the OS. When you restore the OS from here, it installs the latest version you had on that computer.
If you’re using a newer Mac, you can start your machine directly from Apple’s servers using a tool called Internet Recovery. No more digging around for an install disk. An internet connection is all you need. When you reinstall the OS using Internet Recovery, it installs the OS that originally came with your machine, so if you had previously upgraded your OS, you must do so after the OS is reinstalled.
The wizard will take you through each process, but user beware! You can wipe your entire HD this way, and with no OS, you won’t be able to boot it back up. Don’t try this yourself without extensive research or with the assistance of a technical specialist.
Call the Mac Experts at PowerMax to walk you through the process if you’re uncomfortable trying it yourself. We’re always here to help.
Christine is a Technical Support Specialist and Content Writer for PowerMax. Follow her articles as she takes you “Behind the Sasquatch: A Look Inside PowerMax,” an inside look at the day-to-day operations from the perspective of a Woman in Tech. She’ll also post great Tech Tips, helping you get the most of your Mac apps as well as write about some common technical issues and how to fix them. Finally, Christine will periodically post some Tutorials that teach readers how to do things like make podcasts and iPhone apps. Find what you’re looking for in the categories on the right.
If you have a tech question or issue, please don’t hesitate to contact Christine for help.