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Disk Utility can fix certain disk problems—for example, multiple apps quit unexpectedly, a file is corrupted, an external device doesn’t work properly, or your computer won’t start up.

This topic describes how to repair the disk that started up your Mac. If you’re having trouble with another disk, you can repair it with fewer steps. See Verify a disk.

WARNING: To prevent the loss of data on your Fusion Drive, don’t connect it to a Mac that’s using a version of OS X earlier than 10.8.5. See the Apple Support article Only connect OS X Mavericks Fusion drives to OS X Mountain Lion v10.8.5 or later.

Print this page so you can refer to it later. (You don’t have access to the Disk Utility User Guide when you restart your computer in the next step.)
In the Disk Utility User Guide window, click the Share button , then choose Print.
Choose Apple menu > Restart. After your Mac restarts (some Mac computers play a startup sound), press and hold the Command and R keys until the Apple logo appears, then release the keys.
Click Disk Utility, then click Continue.
Choose View > Show All Devices.
In the sidebar, select the disk you want to repair.
Click the First Aid button .
If Disk Utility tells you the disk is about to fail, back up your data and replace the disk. You can’t repair it. Otherwise, continue to the next step.
Click Run.
If Disk Utility reports that the disk appears to be OK or has been repaired, you’re done. You can click Show Details to see more information about the repairs. Otherwise, you may need to do one of the following.
- If Disk Utility reports “overlapped extent allocation” errors, two or more files occupy the same space on your disk, and at least one of them is likely to be corrupted. You need to check each file in the list of affected files. Most of the files in the list have aliases in a DamagedFiles folder at the top level of your disk.
  - If you can replace a file or re-create it, delete it.
  - If it contains information you need, open it and examine its data to make sure it hasn’t been corrupted.
- If Disk Utility can’t repair your disk or it reports “The underlying task reported failure,” try to repair the disk or partition again. If that doesn’t work, back up as much of your data as possible, reformat the disk, reinstall macOS, then restore your backed-up data.

If your Mac has a Fusion Drive and you see a flashing question mark or alert, see the troubleshooting section of the Apple Support article About Fusion Drive, a storage option for some Mac computers.

Have reinstalled OS X 10.5.8 on a G5, but Utilities folder is empty. Probably emptied for disk space prior to this install. How can I get the utilities back; particularly Disk Utility:? Best Free Partition Software in 2018 1. EaseUS Partition Master. EaseUS is one of the very best partition software in the market today. It gives a host of options to the user, including, create, format, resize, move, split, merge, copy, wipe, check and explore. Disk Utility is a popular backup and clone software, which embeds in Mac OS. It is a highly recommended utility software for Mac. With its help, you can create clone image of Mac system from your present computer and restore it to another Mac.

If you continue to have problems with your disk or it can’t be repaired, it may be physically damaged and need to be replaced. For information about servicing your Mac, see Find out how to service or repair your Mac.

Disk Utility defeats other free DVD creators of Mac, for it is pre-installed. Simple Burn is the best DVD creator for Linux. And DVDStyler is the best cross-platform freeware that has the capacity to produce personal DVDs. Next time, install RAM Disk Utility Pro with 1-click. Learn how MacUpdate Desktop can install apps on MacUpdate with the simple click of the icon. Plus, keep all your apps updated.

Partition management software programs let you create, delete, shrink, expand, split, or merge partitions on your hard drives or other storage devices.

You can certainly partition a hard drive in Windows without extra software, but you won't be able to do things like resize them or combine them without some extra help.

Safe, easy to use partition tools weren't always available, and even when you did find something you liked, it was expensive. These days, there are plenty of completely free disk partition software programs that even the novice tinkerer will love.

Whether you're expanding your Windows system partition, shrinking it to make room for an operating system dual-boot setup, or combining your two media partitions for those new UHD movie rips, these free disk partition tools will sure come in handy.

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MiniTool Partition Wizard Free

What We Like

Supports lots of common disk partitioning tasks
Lets you extend the system partition without having to restart
Simulates changes before you save them
The program is really easy to use
Works well in all modern versions of Windows

What We Don't Like

Dealing with dynamic disks is not supported
Some features that look free are only available if you purchase the program

MiniTool Partition Wizard includes more partition management tools than most similar programs, even ones you might pay for.

Not only does the free MiniTool Partition Wizard support regular functions like formatting, deleting, moving, resizing, splitting, merging, and copying partitions, but it also can check the file system for errors, run a surface test, wipe partitions with various data sanitization methods, and align partitions.

In addition to the above, MiniTool Partition Wizard is able to move the operating system to a different hard drive as well as recover lost or deleted partitions. There's also a file recovery program, disk space analyzer, and benchmark tool built in.

Windows 10, 8, 7, Vista, and XP are the supported operating systems.

One thing I don't like about MiniTool Partition Wizard is that it doesn't support manipulating dynamic disks.

of 10

AOMEI Partition Assistant SE

What We Like

Includes an easy-to-use, step-by-step wizard
Changes you make are queued and not applied until you specifically apply all of them at once
Lots of useful features are included
Many of the options are readily available without having to sift through menus
Can run from a bootable program to work with a hard drive that doesn't have an OS installed

What We Don't Like

Some features are only available if you pay for them
Unable to convert between primary partitions and logical partitions
Can't convert dynamic disks to basis disks

AOMEI Partition Assistant Standard Edition has a lot more options that are out in the open (as well as hidden away in menus) than many other free partition software tools, but doesn't let that scare you away.

You can resize, merge, create, format, align, split, and recover partitions with AOMEI Partition Assistant, as well as copy whole disks and partitions.

Some of the partition management features with AOMEI's tool are limited and offered only in their paid, professional version. One such feature is the ability to convert between primary and logical partitions.

This program can be used in Windows 10, 8, 7, Vista, and XP.

You can also use AOMEI Partition Assistant to create a bootable Windows flash drive, move an operating system to an entirely different hard drive, and wipe all the data from a partition or drive.

of 10

Active@ Partition Manager

What We Like

It's really easy to use and understand
Some changes you make can be restored from a backup
Many common disk partitioning tasks are supported

What We Don't Like

Can't copy partitions
Extending the system partition might not work for you
Won't downsize locked volumes

Active@ Partition Manager can create new partitions out of unallocated space as well as manage existing partitions, like resizing and formatting them. Simple wizards make it easy to walk through some of these tasks.

No matter what kind of file system you're using, the free Active@ Partition Manager tool should be able to handle it, with support for all the common ones, like FAT, NTFS, HFS+, and EXT2/3/4.

Active@ Partition Ma

Best Freeware Disk Utility For Mac