Apple's built-in disk management utility for the mac. Erases, formats, and restores volumes and drives.

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31
votes
4answers
76k views

How to resolve error: “Couldn't modify partition map because file system verification failed”?

I upgraded to Lion and decided I no longer want 100 GB of my drive devoted to Boot Camp, I never boot into Windows, I just use it as a VM anyways. So I deleted the boot camp partition using disk ...
29
votes
2answers
15k views

What is the difference between a “sparse disk image” and a “sparse bundle disk image”?

What are the differences between sparse and sparse bundle disk images?
28
votes
3answers
32k views

How do I get detailed SMART disk information on OS X (Mavericks or later)

I'm trying to get a detailed SMART status report on the drives in my Mac. I'm not talking about "Verified," I'm talking about the detailed report that's about 100 lines long listing all the vital ...
28
votes
9answers
119k views

Unable to Resize Partitions

I have recently created a partition on my macbook air running OS X 10.9, and this was to run install another OS instance (Yes, OS X 10.10 Yosemite, but that is an aside to the query I have) on it. I ...
25
votes
6answers
37k views

Resizing or expanding a CoreStorage volume

I bought a new SSD with 750 GB and made two partitions: 600 GB and 150 GB. The smaller one was thought to be a Bootcamp partition one day, but to date it was just another unused partition. When I ...
18
votes
14answers
185k views

How can I repair a disk that Disk Utility says it can't repair?

I have an external hard-disk with a single Mac OS Extended partition. This disk stopped working couple of days ago. I tried to repair the partition with disk utility but no luck. The error message is ...
17
votes
2answers
9k views

hdiutil convert/rsize resource temporarily unavailable

When trying to convert or resize a dmg image I get the error: hdiutil: convert failed Resource Temporarily Unavailable error or hdiutil: resize: failed. Resource temporarily unavailable (35). (...
16
votes
7answers
35k views

What format for my external drive allows use with Mac and Windows?

How can I use my external hard drive on Mac OS so I can modify/edit files on both OS's: Mac and Windows? How should I format it?
13
votes
6answers
56k views

What is the best way to clone a disk between two Macs?

What is the best way to clone a disk between two Macs? I ask this every couple years or so and every time I get the same answer. "Use Carbon Copy Cloner", they say. But the unfortunate fact is that ...
13
votes
3answers
82k views

Disk Utility won't Unmount HD for formatting

I have two internal drives in my 27" iMac (10.8.5). An SSD system disk and a 1TB SATA drive. The HDD has been acting up recently, very slow performance, bad behavior etc. Tech Tool Pro and Disk ...
13
votes
4answers
45k views

“Warning: SUID file has been modified and will not be repaired” after repairing disk permissions

Warning: SUID file “System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/MacOS/ARDAgent” has been modified and will not be repaired. I keep getting this after running Disk Utility to ...
13
votes
2answers
97k views

How can I delete everything from my MacBook Pro before selling it?

I have a Mac that runs Snow Leopard and I intend to upgrade it to Mountain Lion and sell it on ebay. However, I only have one hard-drive, and I'm sure I can't use something in my OS to delete my OS ...
12
votes
1answer
15k views

Can't ever remove partition?

Running Mountain Lion. I added a partition with Disk Utility and then had second thoughts about it. I'd like to remove the partition i created, MacSSD2 and hand over its space back to MacSSD. As you ...
12
votes
3answers
60k views

How can I delete a partition (coreStorage logical volume?) from the Terminal?

I finally understood why Disk Utility will not change the partitions on my HDD, even though I added the most recent one myself (maybe significant: to test Yosemite DP) with it. Now I see it says it ...
12
votes
1answer
8k views

Can Disk Utility format an SD card with FAT32?

In the pulldown for "Format", there are only the following options (other than various Mac OS Extended variations): MS-DOS (FAT) and ExFAT.
12
votes
4answers
6k views

How much data has been written to my SSD over its lifetime?

Is there a Terminal command which will show me how many GB has been written to my SSD through the whole lifetime of the disk? I'm asking because I want to find out how many cycles have been done. SSD ...
11
votes
2answers
5k views

hdiutil: compact failed – Function not implemented

When compacting a sparse image with the hdiutil compact command, it fails with the message hdiutil: compact failed – Function not implemented.
11
votes
10answers
65k views

Macbook HD “Other” all the Sudden Almost Full

As you can see in the below image, my HD "Other" category is almost full. A couple of days ago, I randomly kept getting a popup saying that my disk was almost full. Then I went in and noticed the ...
10
votes
5answers
68k views

Unable to format / erase hard drive

I have an external HD that died on me a while ago and I'm trying to see if I can format / erase it to start using it again. The disk does not show up in Finder but I can see it in Disk Utility. When ...
10
votes
3answers
51k views

Can't create partition on free space with Disk Utility [duplicate]

I have created new partition by selecting free space option and now I can't merge it or recreate it. I have tried to use iPartition to create a new partition on free space but it said I have no ...
10
votes
1answer
516 views

I know how to repair disk permissions. But… Who broke them?

One of the common Mac troubleshooting steps everyone always seems encouraged to try first is to "repair disk permissions" in Disk Utility. This process usually finds random odd problems, fixes them, ...
9
votes
4answers
12k views

What are the sector sizes on Mac OS X?

I read on the HFS Plus Wikipedia page that the default sector size on a Mac is 512 b. However, I also read that Macs support 4kb sectors. How can I determine which I have, 512 b or 4 kb sectors? I ...
9
votes
1answer
27k views

Create new partition in unallocated space with diskutil

I have deleted the first partition on my external HD such that it now has 100GB of free space at the beginning of the partition. I'd like to reclaim that space, but Disk Utility doesn't let me create ...
9
votes
4answers
60k views

How can I resize a partition with Disk Utility?

I have 2 partitions, I reduced the size of one and want to expand the other to fill the now available space. How do I expand the Lion Partition into the empty grey space beneath Macintosh HD ...
9
votes
2answers
9k views

How do I resize OS X main partition when I already have other BootCamp partitions?

Short story: partition resizing using Disk Utility fails because MediaKit reports no such partition when I try to shrink it. I also tried the same while booting from the DVD, same result. Details: ...
8
votes
2answers
6k views

How to fix Disk Utility, About This Mac, and Finder that disagree on hard drive space usage?

Has anyone seen this issue and know how to fix it? Look at the free space reported by running "Get Info" on my hard drive (Macintosh HD) in the Finder, "About This Mac" from the Apple Menu, and Disk ...
8
votes
3answers
12k views

How can I mount an encrypted disk from the command line?

When I type diskutil mount disk3 in the terminal, it says Volume(s) mounted successfully. However, the disk is not mounted and I can confirm this by opening the GUI of Disk Utility.app and also the ...
7
votes
2answers
714 views

Move complete Lion installation to another physical drive

is there a way to completely move my OSX Lion to my new SSD without reinstalling? I came from Windows and Linux to OSX and i thought maybe it is possible to simply change the bootloader config after ...
7
votes
1answer
14k views

How can I reformat a drive that contains an encrypted volume?

After OS X 10.7 came out with its disk-encryption features, I encrypted an empty USB thumb drive just for grins. I never used it, and eventually decided to reformat it as a normal drive for use with ...
7
votes
2answers
65k views

What are next steps when fsck reports “could not be repaired after 3 attempts”?

My Mac Book Pro 13.-" doesn´t get past the grey booting screen with the apple and the spinning wheel (The loading bar appears but when it´s done nothing happens) I have 220 GB in one single ...
7
votes
3answers
16k views

Disk needs repaired… but it doesn't?

I've been noticing some oddities with my computer lately. Applications running slower than normal. Hanging. I decide to run Disk Utility and I get the following statement: So I do what it says and ...
7
votes
1answer
502 views

Disk Utility does not show OK message after Verify Disk

Rebooted and Verified Disk twice. There is no OK message and stops here: Is it a new behaviour under Mavericks, or something wrong? How can I fix it?
7
votes
1answer
15k views

Stuck in a boot loop after failed update to Mavericks, can't reformat HDD

I recently tried to upgrade a 2008 Mac Pro from Snow Leopard (10.6.8) to Mavericks (10.9.2) using the free upgrade available in the App Store. The upgrade seemed to go without a hitch until the ...
6
votes
4answers
59k views

Restore Macintosh HD to its original partition configuration

I seem to have badly botched a Boot Camp installation of Windows 8.1. I used Boot Camp Assistant to create a 200 GB BOOTCAMP partition on my 1 TB Fusion Drive. I then rebooted and failed to install ...
6
votes
6answers
24k views

How to identify and fix files with corrupted / inaccessible disk blocks

I have a late 2011 Macbook Pro, running Mavericks 10.9.2. Its sole HDD is a 750GB drive, formatted with Bootcamp. It's still running reasonably well, but in running a defragment pass on it, I've ...
6
votes
3answers
34k views

I think I messed up the Fusion Drive on my 1TB iMac (with BootCamp)

this is a somewhat similar post to this one (Can't create partition on free space with Disk Utility) but not quite... It started with me creating a BootCamp partition (around 145 GB) for Windows ...
6
votes
2answers
4k views

How can I make my computer believe a disk image is a hardware disk?

I'm trying to do some research on TimeMachine right now. I don't want to purchase an external hard drive, just to learn about some software, and so I'd like to be able to tinker with the settings, by ...
6
votes
4answers
544 views

How to mount disk by UUID or LABEL in OS X El Capitan?

I get the UUID and label of a disk from diskutil info disk0s4 diskutil info disk0s4 Device Identifier: disk0s4 Device Node: /dev/disk0s4 Whole: No ...
6
votes
2answers
10k views

Replace a failed disk in a Disk Utility RAID 1

I have LaCie 2big thunderbolt 2-disk device configured as a RAID1 from Disk Utility. One of the drives appears as "failed", so I unmounted the raid, replaced the drive and plugged it all back in. Now ...
6
votes
2answers
4k views

What terminal command or program can list an SSD's Power On Hours?

I'm looking to script using the unix shell the retrieval of SSD (and HDD) data that disk utility shows in the information window. I'm immediately interested in the Power On Hours and Power Cycle, ...
6
votes
1answer
840 views

How do I clone a hard disk excluding some directories?

In preparation for Lion, I want to make a bootable clone of my system to an external harddisk. I use TimeMachine, but I want to be sure I have a running backup. Of course, there is much stuff on my ...
6
votes
2answers
12k views

How to fix “Error: -5341: MediaKit reports partition (map) too small” after upgrading to a larger hard disk?

I recently bought a new SSD drive, as my stored data amounts outgrew the old one a little bit. After copying all data using dd if=/dev/disk0 of=/dev/disk1, I want to enlarge my system partition, but ...
6
votes
3answers
12k views

Creating boot disk for Windows 7 on MacBook Pro

EDIT: I gave in and burned the DVD from a windows PC and I was able to install Windows on my MacBook Pro with Bootcamp. Sorry, that I don't have a satisfying solution. My goal is to install Windows 7 ...
6
votes
2answers
28k views

How do I change a disk partition map scheme from MBR to GUID Partitions Table?

I just finished the huge download of Mac OS X Lion, started the installer, and now I have a problem. The installer says that I must have the GUID-Partitions Table Scheme. The problem is that when I ...
6
votes
1answer
13k views

Why is a secure erase 'not necessary' for SSD's?

I'm about to trade in a 2010 MacBook Pro with an SSD. However, I'm unable to do a Secure Erase from the recovery disk (as I used to do with mechanical hard drives before selling or giving away a ...
6
votes
2answers
9k views

How do I recover an “invisible” OS X boot option in BootCamp (running on a 2013 MBA)?

Summary Unable to boot into the OS X partition of a 2013 MBA which dual-boots OS X and Windows 8 via BootCamp. Could "Repairing Disk" via "Disk Utility" damage the working Windows 8 partition? What ...
6
votes
1answer
14k views

Why can't I write to the last block of my SDXC card on my MBP?

I have a 64GB SanDisk SDXC memory card which I would like to use with my MacBook Pro and its SD card slot. However, I am having some trouble formatting/partitioning my SD card and I can't figure out ...
6
votes
2answers
420 views

Software update never completes

I have an eMac (PPC G4) with 512 MB RAM, running 10.5.8. When I run Software Update, the "Checking for new software..." process never completes. I have tried deleting my /Library/Caches/com.apple....
6
votes
2answers
2k views

Unable to format pendrive, diskutil error

When I insert my USB Pendrive in my iMac i see this message: I tried to format it both with DiskUtility and with diskutil command in terminal but I get this error: iMac:~ User$ diskutil eraseVolume ...
5
votes
1answer
1k views

External Hard disk 500 GB free but can't copy 8 GB data

I have WD external hard disk, which was working fine. Its MS-DOS formatted. I have downloaded a file in .mkv, which works fine, and isn't corrupted. Upon copying the 8 gb file, it says "The file is ...