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

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20 views

Resize Mac Partition is Disabled - how to partition properly

I have two partitions on my mac book pro. One partition is running os Yosemite and other one is running bootcamp windows 8.1. Yosemite is 75GB and Bootcamp has 673GB. I shrinked the windows partition ...
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2answers
7k views

Can't partition startup disk in Mavericks for Boot Camp

I recently upgraded my computer to Mavericks (I believe I have the latest version, 10.9) and I've been trying for 2 days now to install Windows via Boot Camp on my computer, but it always fails at the ...
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1answer
21 views

How to fix my partition table after messing it up trying to install Linux Mint

I tried to install Linux Mint alongside my working OS X Yosemite. I have a Macbook Air released mid 2013 with a 128gb SSD and 4gb of memory. Well to achieve my aim I first added a partition using ...
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2answers
8k 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 ...
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13answers
115k views

How can I repair a disk that disk utility says it can't repair this disk?

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 ...
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2answers
22 views

Unable to repair hard drive - due to volume assignment problem?

Disk utility and fsck [terminal] both agree that there is problem with my HD. I am curious if someone can help me figure out how I can deal with the problem. Terminal - Normal Mode MacBook-Pro:~ ...
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1answer
19 views

External hard disk not showing up on finder and can't be verified in Disk Utility

My Mac suddendly restarted and now the external hard disk I normally use for Time Machine backups is not working anymore. When I plug it in, it doesn't appear on finder and while it appears in the ...
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0answers
8 views

RAID + FileVault and startup partition

From this answer: Why doesn't FileVault work on a RAID volume? I learnt that it is possible to have RAID and FileVault together. However it seem that the solution is for a separate data volume not ...
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1answer
30 views

Disk Utility reading disk incorrectly; viewing ext4 as JHFS+ and seeing Recovery HD

This is imported from Superuser, I felt like I would have an easier time getting an answer here than in Superuser - it is copy pasted, as below. So, I have some strange issues in Disk Utility and ...
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3answers
2k views

Cannot format MacBook Air SSD, stuck at waiting for disks to reappear

I have a Macbook Air with 128GB SSD and 4GB RAM with OS X Mavericks. I was using my Mac normally but suddenly Chrome got stuck. So I held down the power button and force-shut down the Mac. When I ...
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1answer
135 views

how to fix GUID hard drive corrupted to MBR

I am on OS X 10.9.5 with a late 2013 iMac. I have a 3TB hard drive that has an unusual problem. It is a Western Digital 3TB Red WD30EFRX. I formatted it with two partitions, both 1.5TB. One was a ...
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1answer
36 views

“Unable to unmount volume for repair” message from reformatted SSD in “Option/ALT startup” using bootable USB

I am trying to reformat a Samsung 512GB Pro with bootable USB, and I have manage to get through the prep for the USB. But after the "Option/ALT startup" i click on the USB to begin with and when the ...
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1answer
8k views

How to merge two Mac partitions?

Recently I ran Boot Camp Assistant to install a copy of Windows 7. The "Partitioning Disk" process froze and I force quit it - I know, bad idea - and although I was left with a functioning Mac, I ...
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4answers
9k views

“Couldn’t create temporary file.” error when erasing free space on external disk

I was trying to wipe the free space of an external USB 3.0 disk in OS X (Yosemite) disk utility. However, I receive the following error: EDIT: The disk is formatted as GUID / Mac OS Extended ...
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1answer
44 views

Why can I only have 2 partitions on my 3TB Apple Fusion Drive?

According to Apple, I can only have 2 partitions on my 3 TB Fusion Drive. I do not understand why. Techtool Pro made an eDrive, their emergency boot drive, and Apple made their Recovery HD. It ...
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0answers
22 views

BootCampAssistant “Install or delete Windows 7” greyed out

I need to install a Windows 7 on my MacBookPro but the installation button is actually greyed out. I first managed to install a first windows but i needed it to be bigger, so i deleted the BootCamp ...
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1answer
132 views

Hard drive no longer accessible

This is a 4 TB hard drive formatted in Mac's Disk Utility as a single non bootable Exfat partition with the drive letter G. It worked fine before I decided to make a clone drive of my C bootable ...
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1answer
19 views

Cannot Partition Disk with Disk Utility

I can't seem to partition my disk with Disk Utility or with the Terminal command (see screenshots). Something also happened to my other partition running Mavericks, where it just turned into an "empty ...
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0answers
31 views

Unable to prepare any SSDs for OSX installation

I've tried four different SSDs over the last few months, on two separate Macs, and have been unsuccessful in getting OS X installed on any of them. The first was an OCW, the second and third were ...
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1answer
17 views

I cannot do bootcamp but my hard disk only have machintos HD and Data

The bootcamp said that my disk cannot be partitioned or restored as single partition. I am using macbook pro 15" but idk the version but the graphic card said gt320m 256 MB and 350 GB HDD i5 do i ...
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1answer
25 views

recover partial backup data from a (potentially damaged) Time Machine disk

I am on a MacBook Pro Retina 15-inch, late 2013, with OS X 10.9.5 Mavericks. First of all, to clarify the question, my goal is to create a new, working Time Machine (TM) disk, that has as much as ...
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1answer
42 views

Can't edit partitions with Disk Utility in OS X 10.10

I'm having trouble accessing about 50GB of space on my computer after a failed partitioning attempt. Before you ask, I don't know what went wrong, I just know that now, I can only turn the free space ...
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2answers
35 views

Backup disk suddenly won't work

Here's the error message I get: "An error occurred while copying files. The problem may be temporary. If the problem persists, use Disk Utility to repair your backup disk." When I try to follow that ...
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2answers
4k views

Repartition hard drive with bootcamp on it

I currently have this setup on my Mac- OS X Mavericks 10.9.3, Windows (bootcamp) and a Recovery HD. My question is can I repartition my hard drive to have another partition, using disk utility (resize ...
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1answer
18 views

How to backup and restore MBP hard drive before reinstalling OS X?

My MBP Retina 13″ late 2012 is showing the stop sign and I know that I need to reinstall my OS. I have not got my hard drive backed up with Time Machine. Is there a way in which I can backup my hard ...
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3answers
56k 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 ...
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2answers
3k views

Merging partitions separated by Bootcamp

In the process of installing windows on my MacBook Pro, I managed to somehow partition the disk this way. Is there any way of merging the UNTITLED 3 segment with the Macintosh HD segment without ...
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1answer
29 views

Disk Utility not letting me Partition Disk

A bit of background before I start. I'm trying to install Ubuntu onto my Macbook Pro and so far I've stumbled into a bit of a roadblock. I've also already installed Windows 10 with Bootcamp, I'm not ...
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2answers
39 views

Can't restore Time Machine backup to Macintosh HD

Today I found my Mac shut down. It won't boot again anymore. When I try to turn it on, it just shows the Apple logo, a loading bar and after 1/3 progress it just shuts down again. After some research ...
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0answers
14 views

How to monitor progress of disk decryption in recovery mode

As the title states, I am decrypting an external drive using Disk Utility in Recovery mode, and would like a way to know the progress or completion as well as any errors. Is there a known way to do ...
2
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1answer
21 views

White prohibitory sign on Startup

Have the white prohibitory sign when trying to boot up MBP Retin 13" late 2012 running Yosemite. Have tried resetting PRAM (cmd + alt + p + r) and disk utility has been to no avail so far. Have tried ...
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2answers
41 views

Why can't I boot to Disk Utility (iMac A1418) - It displays a lock and a password field?

Someone showed me their iMac that they recently bought second-hand. It boots normally to the login screen with the PIN (EDIT: it is a PIN and NOT a passcode; the message reads "Enter your system lock ...
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2answers
5k views

diskutil coreStorage in Lion fails to create a concatenated LVG, error -69886

I would like to create a logical volume group (LVG) with two physical disks. Issue The command: diskutil coreStorage create LVGNAME /dev/disk1 /dev/disk2 returns: Started CoreStorage ...
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3answers
6k views

Clone the Windows partition with Carbon Copy Cloner?

I have bought a new Hard Drive and I want to switch from my old disk to my new one. Time machine will do the job for my Mac partition, but not the Windows partition I guess. So I'm looking for way to ...
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2answers
11k views

external hard drive found only by disk utility, cannot eject or mount

I'm using a Seagate GoFlex that seems to have encountered some trouble. The drive does not appear on the desktop or Finder. I've double checked that Finder > Preferences allows for it to appear in ...
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0answers
26 views

Mounted image appears empty in Finder

I decided to reinstall MacOS X from scratch. I have rebooted my mac with Cmd+R, then used Disk Utility to create a .dmg disk image on a USB drive. I then rebooted the computer and verified that I ...
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1answer
663 views

Should I reformat a disk if Disk Utility asks me to?

I have a FAT32 external disc that was suddenly unmounted as I was using it. When I reconnected it and tried to Repair it in Disk Utility, I got the following messages: Verify and Repair volume ...
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1answer
6k views

Macintosh HD not showing up on disc utility

I am trying to do a clean install on my Macbook Pro 13" from 2011. Here is what I did so far: 1) Booted up on my USB Stick with Mountain Lion Installer mounted on it 2) Opened up Disc Utility and ...
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5answers
11k views

Disk Utility hangs prior to resizing partition

When trying to shrink the size of a partition, the period before the actual resizing happens (where Disk Utility says "Preparing to partition disk") hangs forever. I dug into Console to see what was ...
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2answers
56 views

Disk structure error reported in Onyx but not fixable via the Disk Utility in Recovery Mode

On Yosemite 10.10 Onyx returns the following error: Error: -69845: File system verify or repair failed Underlying error: 8: POSIX reports: Exec format error The disk needs to be repaired. I ...
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1answer
29 views

Disk utility unable to change partition type

I'm trying to copy a .img disk image to a microSD. However, when I try to move the contents of the image I downloaded to the microSD, I get this: Same result when copying via Terminal. ...
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0answers
21 views

How do I resize my partition on my Mac? [duplicate]

I'm having trouble resizing my hard drive partition. Before, I was running OS X Lion in the free space above Macintosh HD 2. Now that I deleted the Lion partition, I am unable to resize Macintosh HD ...
0
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1answer
42 views

Finding lost partitions

I am resetting my sister's MBP late 2010 to factory defaults. It's all backed up. I'm reinstalling from the recovery partition currently. Before I started working on it today, it had the very ...
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1answer
33 views

How to rename (main) hard disk back to default? And is the disk default really LVG?

I recently reinstalled OS X, when it asked me to erase the disk I just left it Untitled, since there's no instruction to rename it to whatever on this Apple support page, after restoring with Time ...
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0answers
22 views

How make a ms-dos floppy .img

I'm trying to make a MS-DOS Floppy .img to use in virtualbox, but I don't know how... So far I tried: dd bs=512 count=2880 if=/dev/zero of=floppy.img or dd bs=1024 count=1440 if=/dev/zero ...
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2answers
3k views

OS X Partition not resizable

3 weeks ago I installed Yosemite public beta onto a brand new Macbook Air which arrived with Mavericks pre-installed. To carry out the installation I created a new partition for Yosemite and so had ...
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3answers
26k 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 ...
0
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1answer
47 views

Does OS X's Disk Utility create hardware RAID or software RAID?

I created a mirrored RAID (RAID 1) using 2 Western Digital 2TB external hard drives before, using Disk Utility on a Mac. For this, it should be software RAID. And then I got a WD Thunderbolt Duo ...
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2answers
87 views

I can't resize my macintosh HD drive on os X 10.9.5

I have checked similar questions but didn't find an answer that worked. I have a macbook pro late 2013 with OS X 10.9.5. I have the OS X on the Macintosh HD drive (Mac OS Extended (Journaled)), ...
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1answer
1k views

Failed to make bootable USB drive and now I can't even format it

I want to do a fresh install of Yosemite and I got a brand new 8GB flash drive and I followed this tutorial. I formatted the USB drive and was copying the Yosemite installer, however I got the ...