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

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MacBook not able to boot using OS X (Yosemite) after partitioning the Macintosh HD (hdd) while installing Kali Linux

I tried to partition the HDD using GParted but it didn't work out. Maybe because I messed up. So after cancelling the whole process, I rebooted my laptop. When I tried booting through OS X, it did not ...
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2answers
911 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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2answers
3k 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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2answers
26 views

How to Create Images with Yosemite

I have a Mac Mini configured just the way I like it with 10.10.2 installed. I need to deploy that to a bunch of other computers around campus. The usual process for me in the past has been to use an ...
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0answers
98 views

200GB of lost space! Difference in file size between finder and disk utility

I have installed yosemite and I am trying to have a backup using time machine. Time machine gives an error that the external drive size is not sufficient. And here begins the adventure... I have an ...
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1answer
1k views

cannot boot. volume disappeared from boot option after Disk Utility (GUI) repair

I have a 13-inch MBP with the latest OS X version. Problem Yesterday, I went to the Recovery Mode and performed Repair on my boot volume. I was not having a problem, but I just wanted to verify and ...
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0answers
20 views

Can't erase unmountable external HD

My external HD isn't mounted and can't be repaired by Disk Utility. However, I'm also unable erase the disk: $ diskutil list disk2 /dev/disk2 #: TYPE NAME ...
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1answer
41 views

Problems with target disk mode, HD does not show in Finder/Desktop (only in Disk Utility)

I have a MacBook Pro which goes straight to Disk Utility when I try to start it (it totally froze and I forced it off and on). And no luck in repairing the hard disk (Disk Utility can't repair…) I am ...
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1answer
28 views

Force stuborn drive to unmount

I have a single partition disk whose filesystem will not mount properly. I don't care about the data and I would like to try reformatting the disk but I keep getting errors related to a failure ...
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2answers
36k 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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1answer
25 views

External Drive showing only in system profiler

I have had a 1TB Western Digital Ultra external hard drive for nearly year. Out of nowhere it will not show in disk utility but it does show in system profiler. I have a Macbook pro mid 2012 running ...
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1answer
61 views

Disk Utility message “Updating boot support partitions for the volume as required”

Finder crashed on a external drive which caused an abrupt eject. I rand Disk Utility over the drive and the operation finished with the message: Updating boot support partitions for the volume as ...
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2answers
6k 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
69 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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2answers
3k views

Unhide Partitions via Terminal

Is there any way to unhide partitions that have been hidden by a third party partitioning tool on a Mac using nothing more than Terminal via a Mac OS X Boot CD or USB stick? Edit These partitions ...
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2answers
39 views

How does disk utility work while the system is live? (e.g. partitioning/resizing the OSes partition)

How is it that Disk Utility allows you to resize the partition that OS X is botted from live, while the OS is running? Can there be problems doing this? I would have thought that booting into recovery ...
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1answer
5k 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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2answers
4k views

Restore Recovery HD partition from Yosemite downgrade

I recently got back to Mavericks from Yosemite, everything went fine. As I normally do, I checked my HDD with the Disk Utility and found some trouble, then I boot on recovery mode to fix my HDD. I ...
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1answer
25 views

Resizing Macintosh HD partition to use free space

I recently deleted a partition and have 60GB of free space. I would like for my main partition to use that, but whenever I go to resize it, I get the error "You can’t perform this resize unless it has ...
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17 views

Brand new 15in retina

I bought the mac then hooked up Time Machine and started restore to Mac HD. All was fine until the end when the backup from on 6 minutes to go for a couple of hours. No progress at all. So after ...
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0answers
23 views

What to do after mistakingly shrinking disk in Disk Utility?

I only had 1 volume on my hard drive. I tried to shrink it with Disk Utility - thinking it would resize the disk and the other space would be available to create another disk with. I didn't add any ...
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1answer
121 views

How to fix the error: “This disk doesn’t contain an EFI system partition”?

I get the following error and cannot start Bootcamp after accidentally deleting the EFI-partition of my main drive. This disk doesn’t contain an EFI system partition. If you want to start up ...
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4answers
7k 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 ...
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0answers
58 views

Restore on new drive: Time Machine versus “Restore” via Disk Utility

I am about to install a new 240GB OWC Mercury Electra 6G (6Gb/s) SSD into the main drive bay of my MacBook Pro, moving the original Apple-installed 120GB 3G (3Gb/s) SSD into the optical bay using an ...
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5answers
16k views

Disk Utility won't allow me to delete and resize partitions

I'm running OS X 10.9, and I had a linux partition when I updated from 10.8. Since I updated I can't boot on linux, which is no big deal for me. However, I would like to delete the partition that is ...
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1answer
23 views

Backing up a RAID experiencing I/O issues

I recently began working for a company that has an OS X Server with a PROMISE Pegasus Thunderbolt RAID (RAID 5) attached as a file server. Within my first couple of days, it became apparent that users ...
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2answers
3k views

Unable to Partition a new Macbook Pro

As a brand new Mac user this might be my naivety or an issue with the OS. I bought a new Macbook Pro today and wish to partition the disk to allow Windows to be installed and Linux too. I was ...
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0answers
53 views

Mac OS X dosen't recognize hard disk

I have replaced my CD drive with a Western Digital 750GB hard drive using the iFixit guide. My Mac for some reason throws error on any interaction with the hard drive, for example on disk utility ...
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0answers
25 views

Partitions shows it is 2GB when it is actually 120GB

After messing with the partitions to install Ubuntu, the hfs+ partition which I use for my user data went from 130GB to 2GB (OSX is on a separate partition). Disk Utility shows this partition as ...
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1answer
31 views

Partition of harddisk lost/unusable

I'm using OS X Yosemite - version 10.10.2. I have 1.12 TB fusion drive on my system. Recently I wanted to make a partition on my system, while making the partition on the system using disk utility ...
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1answer
13 views

How to rename disk indentifier?

I created 5 partitions on my portable-drive via DiskUtility. $ diskutil list disk2 /dev/disk2 #: TYPE NAME SIZE IDENTIFIER 0: ...
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2answers
2k 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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2answers
6k 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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2answers
4k 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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1answer
47 views

Is undoing Yosemite's CoreStorage conversion dangerous?

I tried to make an 8 GB partition on my hard drive so I could make it into a bootable drive, like Recovery HD but without the need to redownload the OS, but for some reason Disk Utility wouldn't let ...
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1answer
33 views

Remove partition and restore the space without erasing

Time ago I split the hard drive (500gb) in two partitions (250 each), now I don't need them anymore, so I have first erased successfully one partition and now I have still the second one (Mac HD 2) ...
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1answer
42 views

Flashing folder icon appeared once after changing Macbook hard drive

About 2 weeks ago, I updated my late 2011 Macbook Pro hard drive to a Crucial MX100 solid state drive. The drive installation and data migration went fine with no issues, but today I found the ...
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1answer
77 views

Why does Disk Utility show one “Macintosh HD” as a logical drive and another that says core storage physical volume

I am trying to figure out why I have 2 Macintosh HD Drives Appearing in disk utility. One of them i can mount and shows it as being a logical drive and the second one i can't mount but it says it has ...
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2answers
63 views

Is my hard drive already dying?

Although everything is working fine with my Macbook Air from Mid-2013, I have a few errors that bother me. Here they are: Onyx says this: The SMART status was not verified because it is not ...
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1answer
103 views

How do I regain unaccessible free space after a failed Boot Camp install on a non-Fusion drive?

Firstly - I know this has been answered, but I am hoping for a more broken down answer, as I am not quite so technically minded, but I can follow instructions! So in summary I have tried to install ...
2
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1answer
3k views

Resizing dual boot partitions in Yosemite

I have a dual boot Macbook Air with Yosemite and Ubuntu. I would like more space on my Ubuntu partition and need to therefore reduce the size of the Mac partition. I assume this will cause some damage ...
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0answers
14 views

Diskutil can't add drive to mirror

bash-3.2# diskutil appleraid add member disk3 disk8 Started RAID operation on disk8 LookingGlass Unmounting disk Repartitioning disk3 so it can be in a RAID set Unmounting disk Can't write the RAID ...
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1answer
63 views

Trying to boot up on Mavericks USB Install Drive, receive prohibited sign on screen

I have a late 2011 Macbook Pro and I had Mavericks, which ran just fine, but I upgraded to Yosemite after hearing some good reviews. I didn't back it up in time machine. It made my laptop extremely ...
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1answer
5k 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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1answer
50 views

Replace Recovery HD with a “bootable drive” formatted partition?

A while ago, I had the idea to use the bootable Mac OS X USB drive-making procedure on a hard drive partition, so that I could basically have a version of the “Recovery HD” that doesn’t need to ...
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1answer
52 views

I can't create a second partition in Mac

When I go to my disk utility, my main hard gives me results like this It's showing capacity 499gb but only remaining 10mb. Now please see the second image What's happening with my Mac?
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2answers
75 views

After erasing 200 GB I need to repair it using the Recovery HD

I was cleaning my MacBook Pro, erasing all unused files I had on it. After that I decided to erase the free space, so I will have all my files organized and cleaned the "used space". After that I ...
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0answers
35 views

My Macbook Air doesn't recognize my USB

I've always used my USB on this computer. The only issue i would have is that it wouldn't always appear on screen, but i would just eject it and put it back in and it would all be ok. Today for some ...
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0answers
31 views

Is there a way to manually repair a CoreStorage volume?

I was playing around with CoreStorage on a test disk and used the undocumented commands cs addDisk and cs removeDisk. The addDisk command worked just fine and was able to expand a logical volume ...
2
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1answer
476 views

Is my SATA cable damaged?

Macbook Pro Mid 2012, original SSD. TLDR; Why could I clone my unmountable drive from an external enclosure but not internally? My SSD broke down a few days ago. It was detected, but I was unable to ...