Repairing your Mac's hard drive directory with DiskWarrior

When hard drive corruption occurs, your Mac may behave strangely (e.g., loooong pauses in Finder or Open/Close dialogs). In severe cases your Mac will refuse to startup. When Apple's Disk First Aid (a feature of the Disk Utility) fails to fix a corrupted drive, turn to DiskWarrior.

Alsoft's DiskWarrior 4 is the hard drive repair champion. Have it on hand before problems arise.

Caution: The latest DiskWarrior 4.4 DVD cannot start up on Macs introduced on or after June 11, 2012 (i.e., the newest MacBook Air, MacBook Pro, and iMac).

When should I run DiskWarrior?

These are good times to take a break and run DiskWarrior:

  • Before installing a Mac OS X upgrade (e.g., 10.6 to 10.7) or update (e.g., 10.7.1 to 10.7.2).
  • When your Mac does not complete startup, i.e., the desktop never appears.
  • When two or more applications start behaving strangely.
  • When you want assurance your hard drive is in good condition.

If DiskWarrior repairs a serious error (see "Review DiskWarrior's report" below), it typically has also resolved the problem(s) that prompted you to run it.

Even if DiskWarrior finds no serious errors, it's helpful to know hard drive corruption is not the source of any problems.

Print this recipe

If you're reading this on the Mac that's about to run DiskWarrior, print the PDF version of this page to have it handy while DiskWarrior is repairing your drive.

Note: Resist the temptation to print this Web page from your browser – the screenshots get separated from the related instructions.

Restart from the DiskWarrior DVD

If your Mac started up from its internal hard drive, DiskWarrior can't repair it. So you must start up your Mac from the DiskWarrior DVD:

  1. Insert the DiskWarrior DVD into your Mac and wait for the disc to appear on your Desktop.
  2. Choose "Restart" from the Apple Menu.
  3. After the screen goes blank, hold down the "C" key until the Apple logo appears on the screen. The "C" must be pressed before the end of the startup "chime."
  4. Wait 5-10 minutes for your Mac to start from the DVD. Starting Mac OS X from a DVD is a lot slower than from the internal hard drive.
  5. Click the "Agree" button on the DiskWarrior license window.

Notes:

Some newer Macs with wireless keyboards have timing issues when starting up from any DVD. Instead of pressing the "C" key immediately upon start up (step 3 above), press the "Option" key. This will bring up the Startup Manager which will allow you to choose the DVD as a startup disk. If your wireless mouse is not working in the Startup Manager, use the right- or left-arrow keys to choose the DVD, and then press the "Return" key to continue starting up.

If your Mac fails to start up from the DiskWarrior DVD, it's likely the version of Mac OS X on the DVD does not support your newer Mac. In that case, you should contact Alsoft Sales to order an updated DVD.

Wait for DiskWarrior to scan for hard drives

Select the hard drive to be repaired

Select the drive you wish to repair from the menu of all available drives.

DO NOT select your Time Machine backup drive. DiskWarror cannot repair a Time Machine drive.

Begin the repair

Click the "Rebuild" button to begin repairing the drive.

Wait for DiskWarrior to complete the rebuild

DiskWarrior's reports the progress of rebuilding the hard drive directory. The top progress bar corresponds to the 10 rebuild steps; the bottom bar shows the current step.

The 10 steps will take from 5 to 30 minutes (or more) depending on the number of files on the drive.

Review DiskWarrior's report

Red text indicated errors that have been repaired.

Repairs to icons, dates and file attributes are useful but typically do affect overall system performance.

"Incorrect values in the Volume Information were repaired" indicates the disk directory was seriously damaged. Your Mac will perform much better after this type of repair.

Replace the drive directory

Wait for DiskWarrior to create a new disk directory

DiskWarrior takes a minute or so to replace the disk directory.

If DiskWarrior reports there is not enough free space on the drive to do a fail-safe replacement, it's actually safe to tell it to proceed.

Do not save the report

If the DiskWarrior report included any red text, DiskWarrior will offer to save the Step 10 report. Click "Don't Save" because there's no need fior this report once the drive has a new, clean directory.

Repair additional hard drives

If your Mac has additional hard drives (other than your Time Machine backup drive), it's a good idea to repair each of these drives.

Quit DiskWarrior to restart

Choose "Quit" from the "DiskWarrior" menu (top menu bar) to Restart your Mac from its newly repaired internal hard drive.

Eject the DiskWarrior DVD

After Restart, your DiskWarrior DVD will mount on your Desktop. Dragging the DVD icon to the Trash will pop up this dialog window. Simply press the "Eject All" key.

You can avoid this dialog by pressing the Eject key on your keyboard (instead of dragging the DVD icon to the Trash).