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

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189 views

Boot from USB in macbook pro mid 2012

I have removed everything from my macbook pro. Now, how can choose USB as a startup disk? I tried using option "SHIFT" keys also cmd+R. Nothing is working. How can I solve it? I am using Mid 2012 ...
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1answer
440 views

Cannot install OS X in recovery mode

I want to reset my iMac (late 2014, 1 TB Fusion Drive) to factory settings. As I want to set it back to Yosemite, I am using Internet Recovery (Command-Option-R) as I have installed El Capitan in the ...
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0answers
48 views

External disc partitioning gone wrong

I would appreciate any help as this situation is beyond my skills. I was trying to follow an internet instruction for putting an OS X Installation on my WD external drive using my MacBook, to ...
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0answers
88 views

What are the advantages or disadvantages to Logical Volume Groups vs traditional partitions

I recently installed a new 3TB hard drive on a Mac Pro (3,1) running yosemite. With other hard disks, I had previously installed the hard disk and then erased in disk utility getting the traditional ...
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25 views

Restore RAID Mirror?

I had a 3TB mirror using Apple software RAID on Mavericks—the two disks are in a USB3 JBOD and the USB3 card in my Mac Pro only works with Mavericks or older. Last night I demoted one of the disks so ...
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2answers
89 views

Disk Utility stuck at exit code 0 during partition restore (in Recovery Mode)

I have an iMac running OS X El Capitan. I tried to use the disk utility in normal boot to restore two partitions into one but it would exit with an error (exit code 8) and delete the second ...
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0answers
47 views

Scripting a Partition Scheme for CoreStorage - Mac

I've read a lot of information about the CoreStorage/Fusion Drive setup. In our environment, we work on a multitude of configurations of Macs, many with multiple operating systems on them. As such, ...
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1answer
116 views

Boot Camp failed and reduced Macintosh HD partition from 3TB to 1,46TB

What went wrong? I created a new partition with Boot Camp Assistant (OS X 2,25TB | WIN 850GB), but during the partition process, the iMac suddenly restarted. When it got back on the Fusion Drive's ...
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1answer
125 views

Help partitioning “free space” with utility disk

I've been trying to partition my harddrive to have ~50 gb of unallocated space (right now there's one partition with the operating system on it, so I would like to have that plus the free space). This ...
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1answer
44 views

Is there an easy way to install Linux similar to Boot Camp?

I've so far been using Disk Utility to partition my Mac's drive and install Linux, but is there an easier way to do it, using something similar to Boot Camp, or a third-party software application that ...
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1answer
72 views

Startup Disk Full: Core File

The storage on my start up disk is being consumed by some kind of core files labeled as cores:1234 (numerical digits change). I downloaded OmniSweeper, which helped me locate these files and aware ...
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2answers
2k views

Has El Capitan Disk Utility Removed Encryption Options?

With Mavericks I would unlock an encrypted disk using "Disk Utility", but in El Capitan the "Unlock" button isn't there.
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40 views

Merge all partitions back to single volume

I was trying to install windows 10 on my Retina Mid 2015 MBP using bootcamp, and ran into a few problems during the installation. Without going into too much of detail, this is what i have right now, ...
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1answer
60 views

How to resize the main volume to its original or full size?

I followed the instructions mentioned in one of the threads on this community to expand the Macintosh HD volume to its full volume. I rebooted with cmdR to Recovery Mode, opened Terminal, entered ...
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0answers
17 views

How to fix this hard disk on a virtual machine?

I have been using OSX on a virtual machine for some time, for developing purposes. From today, I'm starting to have hard disk issues. The Disk Utility Tool says that the hard disk has 107.37 GB, but I ...
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1answer
1k views

Bootcamp Failing with Error: “The startup disk cannot be partitioned or restored to a single partition.”

I have a 21.5" Mid-2010 iMac i3 in which I am trying to install Windows 8 on. When I went into bootcamp, I received the ever so common error of: When I went to the newly designed disk utility, it ...
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0answers
12 views

Schedule regular filesystem verification

I recently had a baffling several days troubleshooting some odd network problems, which was eventually narrowed down to my MacBook's Wifi adapter and then finally fixed by performing a disk repair to ...
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0answers
72 views

How to create (the missing) El Captain recovery partition? [duplicate]

I upgraded from Snow Leopard to El Captain. Before upgrade I had a bootcamp partition, and a third FAT32 partition. this caused some complications in the upgrade process and I had to delete the El ...
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0answers
12 views

can I recover merged HFS+ partition with TestDisk

I have merged three HFS+ partitions into one using diskutil. The partition in the middle has some very important files. Using Stellar Phoenix Recovery's recover lost partitions option, I could see ...
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0answers
202 views

SD Card mounted but not accessible in Finder (OS 10.10.5)

On an early 2015 MacBook Air running 10.10.5, Finder will not show SD cards, despite the disk showing up in Disk Utility. In Finder preferences, I have set external disks to be shown on the Desktop ...
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0answers
192 views

After installation of El Capitan, Bootcamp: “A disk read error occured”

Prior to installing El Capitan, my Windows 8.1 installation was running fine and dandy. Now when attempting to load into Windows via rEFIt, I am faced with A disk read error occured. Press ...
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1answer
48 views

USB Hard Drive HFS+ Encrypted Partition Formatted / Recovery

I have a WD 1TB USB External Hard Drive that was accidentally formatted. I had formatted the disk and started writing an ISO to the disk (less than 5 seconds), when I realized it was to the wrong one. ...
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1answer
398 views

How to make Macintosh HD size the same as SSD

So today, I tried dual-booting my late 2013 rMBP on El Capitan with Windows 10. I got to the step within Bootcamp where it was partitioning my SSD, and I went ahead and played a game of Super Smash. ...
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0answers
23 views

Are slow format speeds indicative of more severe hard drive problems?

I have an mid-2011 iMac, that has 4GB of RAM and a 500GB HDD (not SSD). Over the past few months I have experienced: Fairly frequent beach balls/general system slowdowns A worrying number of errors ...
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3answers
5k views

Mount Ext4 on El Capitan

I recently installed OS X 10.11 on my Mac. I tried to read a SD card with an Ext4 partition which wasn't even shown in Disk Utility, although diskutil did show it as a Linux partition. I can't seem ...
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21 views

Can't find storage after fixing EFI system partition error

I followed How to fix the error: "This disk doesn’t contain an EFI system partition"? In the final step sudo dd if=/dev/disk1s1 of=/dev/disk0s1 I cloned an existing ESP from an internal ...
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0answers
61 views

Disk utility reports wrong partition size

I am running El Capitan and recently deleted a bootcamp partition. However, I have noticed that Disk Utility is giving me erroneous values when it comes to partition size. When I click on the HDD, it ...
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1answer
543 views

OS X can't unmount disk

My 1TB LaCie Rugged THB decided it was a good idea to stop working all of a sudden. If I open it in disk util I sometimes see an actual name of a partition, but most likely it's not the real name. In ...
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1answer
649 views

Creating a partition in unallocated space

I left some unallocated space on my external HD (around 200 GB) and now I would like to create a partition on it using gpt in terminal since the Disk Utility tool on El Capitan is not even showing the ...
2
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3answers
2k views

How can I resize a partition on OSX 10.10.5

I have a Mac with OS X 10.10.5 on a HD which had 4 partitions. Using Disk Utility I deleted one of the 4, intending to slightly grow the 3rd (containing the OS), leaving space for a new partition to ...
2
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0answers
186 views

Fixing damaged hard drive after OSX update

I recently tried updating my Macbook Pro Retina to OSX El Capitan, however believing this to be a simple routine update, I did not backup my computer. Of course, the update was unsuccessful, somehow ...
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0answers
61 views

Can't format new SSHD?

I just got a new SSHD, but when I tried to put it in my early 2011 13" MBP and format it from a bootable drive, Disk Utility kept giving me the error message: could not mount disk0s2 with name (null) ...
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1answer
52 views

Stuck on 'Preparing to partition disk'

When I add a new partition it gets stuck on 'Preparing to partition disk'. The new partition is in some empty space in the middle of the disk. As a result of the partition not being there, Windows ...
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0answers
226 views

Missing SSD space on MBPr 13, El Capitan

I have the following problem: I had two partitions, one was ~190 GB, and another ~60GB. Then I wanted to delete the second partition and resize the first one. The deletion went well (I suppose), but I ...
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0answers
117 views

Recovery mode Disk Utility can't see new internal hard drive

Lots of similar questions, but no one seems to be having the exact problem I am. Hard drive on my mid-2012 MBP (Mavericks now, but originally Lion) died; I do have backups (including a clone of the ...
2
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1answer
204 views

Deleted Macintosh HD. Need to create a new partition/ partition table

I was trying to install El Capitan. I went to erase Macintosh HD in recovery> disk utility as I wanted to do a clean install. It then deleted the Macintosh partition then gave me an error code saying ...
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1answer
490 views

I removed Boot Camp the hard way, but then I got a Windows error anyway. Should I be concerned?

The short version: I was running Boot Camp on my Retina MacBook Pro, but I decided just recently to ditch it because I never use it and I'd like to reclaim the space. The official method of removing ...
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0answers
130 views

how to resolve disk partition issue in OSX 10.10.5?

Using Boot camp assistant I have created a partition and installed Windows 7 OS to work on both Mac as well as windows (Dual boot). But later on deleted the windows OS partition(Could not remember how ...
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0answers
48 views

How do merge the free space to my Macintosh HD partition?

I have approx. 370 GB of free space from which I want to merge 200 GB to my Macintosh HD disk. Can anyone please help me on this? I am not even getting the resize option there. System version: ...
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2answers
349 views

How to Erase External USB Drive Which Won't Mount & Isn't Recognized

Before starting, let me mention that I have ALREADY read the following thread in its entirety, and it did not help my situation: https://discussions.apple.com/thread/4832305?start=0&tstart=0 I ...
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1answer
255 views

Is it unusual for “Verify Disk” on Disk Utilities to take so long on a Time Machine drive?

I have an external 3TB FW800 drive set up to be my Time Machine drive. I noticed some unusually high drive activity, and opened up Time Machine to see if it was backing up. Nope, TM showed previous ...
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1answer
30 views

Can I use the Recovery Partition on one startup disk to repair another (internal) disk?

I have an SSD and an HDD in my Macbook Pro (Yosemite) and I recently cloned the HDD to the (new) SSD. The SSD is now unhealthy, for reasons unknown and Disk Utility recommends repair from the ...
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0answers
15 views

Use diskutil without firmware password

Diskutil found some problems on my drive that need to be fixed in recovery mode. However the it department installed a password in the firmware. Is there anyway to start diskutil without the ...
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0answers
7 views

How can I re-allocate the whole space for just one partition? [duplicate]

I'm running OX X 10.10.5 on my MBP with 500GB SSD. When I initially configured the computer I've created a setup with a boot loader so I was able to boot into Linux too. Since I'm using virtual ...
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0answers
90 views

How do I change the password on a Time Machine backup image?

I've tried using Disk Utility, but after entering the current password, I get a small dialog reading Unable to change password for “$image.” (Inappropriate ioctl for device). I've also tried hdiutil ...
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0answers
109 views

OS X - USB key Fat32 cannot be open device in Disk utility -

am trying to reformat a brand new USB key ( EMTEC Click2.0 16GB Flash Drive) which is FAT32 formatted ( default) as I need to store oversized files ( > 4GB) to OS X Extended Journaled The key is ...
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1answer
654 views

How to create a new partition for OS X, then remove the original one

I want to clean install a new version of OS X, so I was thinking to create a separate partition, transfer all applications and settings from my old system and then remove the old partition and make a ...
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1answer
82 views

Time machine backup or File Vault encryption of encrypted disk image

I have a small encrypted disk image on my Mac (Yosemite), containing account numbers, tax reports and such. I created it using Disk Utility, from folder, which I subsequently safely deleted. I am also ...
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0answers
43 views

Bootcamp problems have left my hard drive a mess

I have been trying to install Windows 8.1 via Bootcamp, and have had several problems that have resulted in failures (those are perhaps a different post). I'm using Yosemite. Currently when I run ...
0
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1answer
119 views

Resizing HFS+ volume after cloning

I cloned a disk containing an HFS+ volume to a larger disk using the command line dd utility. Now I want to grow the HFS+ volume to fill the new disk. There's an EFI partition before the HFS+ volume ...