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

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21
votes
3answers
51k 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 ...
15
votes
2answers
3k 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?
11
votes
2answers
37k 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 ...
10
votes
7answers
16k 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?
10
votes
1answer
4k 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.
9
votes
6answers
25k 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 ...
9
votes
1answer
8k 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 ...
9
votes
1answer
351 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, ...
8
votes
2answers
5k 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
2answers
7k 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
9answers
21k 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 ...
7
votes
2answers
673 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
2answers
4k 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). ...
7
votes
2answers
22k 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 ...
7
votes
4answers
36k 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 ...
6
votes
4answers
5k 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 ...
6
votes
5answers
2k 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
1answer
468 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
3answers
7k 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
2k 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
6k 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 ...
6
votes
1answer
6k 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 ...
5
votes
5answers
19k 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 ...
5
votes
1answer
820 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 ...
5
votes
4answers
7k views

How do I repair permissions of a specific directory?

I want to repair permissions of a user defined directory along with it's subdirectories. How can I do this? So far, I've looked for options in finder and tried to drag the folder into Disk Utility. ...
5
votes
1answer
2k views

How can I tell which volume the operating system is on?

I'll admit that I am kind of rolling multiple questions in to one here so please forgive me and try not to knock me for it. I am new to Mac but I'm trying to port one of my Java applications to OS X. ...
5
votes
2answers
3k 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 ...
5
votes
2answers
1k 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 ...
5
votes
1answer
4k views

What kind of encryption does Mac OS X Extended (Journaled, Encrptyed) use?

Since my primary hard disk is encrypted with FileVault2, I also wanted my backup drive to be encrypted. I plugged in my external drive, brought up Disk Utility, and went to erase/format the disk. I ...
5
votes
2answers
4k views

What are “dmgpart” files and what tools can create, merge, or manage them?

I downloaded something that came as three large files: One was a *.dmg (a disk image file, which I expected) and two more were *.dmgpart files, which I haven't happened to see before – I never ...
5
votes
2answers
19k 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 ...
5
votes
1answer
579 views

Presence of a Linux partition causes FileVault2 setup to fail

I'm currently dual booting Mountain Lion and Ubuntu 12.04 on a rMBP. Everything works fine, but enabling FileVault fails with the error message: "Some information was unavailable during an internal ...
5
votes
2answers
402 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 ...
5
votes
1answer
4k 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 ...
5
votes
2answers
391 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
145 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?
4
votes
3answers
8k 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 ...
4
votes
1answer
3k views

How do I erase an encrypted TimeMachine drive on Mountain Lion if I've forgotten the password?

My question is similar to this question. I have a USB drive that contains an old encrypted backup. I don't remember the password and don't care about loosing the backup - I just want to be able to use ...
4
votes
3answers
449 views

Copying Time Machine backup, destination takes more than original size, are hardlinks being expanded?

I'm copying the backup folder of Time Machine, but it's taking too long, the backup is 90GB and the copy already reports 160GB and there's 60% to go yet, so I suspect it's copying hardlinks as ...
4
votes
2answers
368 views

How to checksum for a DVD under Panther?

I'm helping a friend checking if a DVD was burned properly but he's saying that under Panther there's no Images menu in Disk Utility.
4
votes
1answer
4k 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 ...
4
votes
2answers
5k 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 ...
4
votes
2answers
18k views

installation stuck in a loop due to damaged HD

Right off the bat I'll admit it was stupid to jump into trying to install a new version of OS X to the only partition without having taken adequate precautions (no backups or recovery disks), but ...
4
votes
2answers
10k views

Deleting a partition in Disk Utility fails. (Error: -69879)

This is the output in Disk Utility: Disk Utility cannot modify this disk because it contains CoreStorage physical volumes. Use command line distil instead. The selected partition won't be ...
4
votes
2answers
2k views

Optimal method to test an external hard drive?

I've got an HFS+ formatted external drive that is starting to act a bit funny, mainly causing my mac mini (finder) to freeze up on occassion when accessing it. Fearing imminent failure, what is the ...
4
votes
2answers
119 views

Move some free space to Macintosh HD (Startup Disk)

On my mac hard disk, Macintosh HD (Startup Disk) is almost full, I need to increase the size of Macintosh merging some free space from my another partition. But I tried all possible ways, free space ...
4
votes
1answer
2k views

Can I partition an iPod (nano, classic, shuffle) for use as a flash drive?

I have made an iPod nano appear as a flash drive by going to iTunes and checking "Enable disk use." However, I am short of a large enough USB key to hold a bootable Windows 8 installer for use by Boot ...
4
votes
2answers
3k views

Why does OS X now think I have two partitions on my external USB drive (plus random connection issue)?

I have an external USB drive that I have plugged into a USB hub, which gets unplugged from my computer about once a day. Most of the time I remember to unmount the drive before disconnecting so that ...
4
votes
5answers
9k views

Unable to increase Macintosh HD partition size with data in a subsequent partition

I can't make my main Macintosh HD partition bigger. It's limited by the FAT partition in the middle, which seems to be frozen, I can't move it down to make space for my main partition. To get some ...
4
votes
3answers
1k views

How to create a bootable USB drive for Disk Utility?

Disk Utility says my boot drive need repair. Unfortunately my DVD drive is toast, so I can't boot from the install DVD and make the repair. Is there a way I can create a bootable USB drive and ...