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

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3answers
6k 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 ...
0
votes
1answer
522 views

External Harddrive is showing in System Information but not Disk Utility

My harddrive crashed last night and since then I have not been able to access it on my Macbook Pro. I've restarted both my computer and hardrive multiple times and I've experienced the same result. It ...
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0answers
23 views

Hard disk doesn't show on boot after erasing with Disk Utility

I have inserted a new disk. It shows after holding the option key. Then I opened Disk Utility and successfully formatted the disk. I restarted and help option but now I can't see my hard disk. I ...
0
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1answer
23 views

Can't re-enable FileVault after growing `system` partition

I recently disabled FileVault in order to grow my system partition. This ended up being rather more complicated than expected, but it worked out in the end. Now that I have resized the system ...
9
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12answers
113k 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 ...
2
votes
1answer
75 views

exFAT-formatted external drive loses folders

I have an exFAT-formatted 3TB USB drive connected to an iMac running 10.10.3. The system lost power and when it came back up, the drive wouldn't mount. I tried Repair Disk in Disk Utility, and it ...
2
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0answers
30 views

Hard disk corrupt twice in 24 hours

My Macbook Pro 13" (2011) had a Seagate 1TB hybrid drive installed as a secondary drive some 4 months ago. Yesterday the volume somehow became corrupt and unable to mount. I managed to format it using ...
2
votes
3answers
5k 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 ...
2
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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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0answers
28 views

Initialize 6 TB internal hard drive

I've found it both economical and flexible to use a docking station with internal hard drives (the ones that look "naked", i.e., have no plastic casing) for backups. I use this docking station to ...
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0answers
75 views

diskutil resizeVolume noob

Back story : After I installed Windows with Bootcamp, I wanted to make another partition where I'll install Linux, but couldn't do that from Disk Utility because I found on the internet that ...
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0answers
70 views

Broken fusion drive - SSD size is 0B and 'No CoreStorage logical volume groups found'

Some context first: I have late 2012 iMac 27" with 1TB fusion drive. Some time ago, for whatever reason, the SSD drive became visible in Disk Utility. I happily used the drive for Yosemite and ...
17
votes
3answers
13k 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 ...
0
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1answer
67 views

mid-2009 macbook pro - erased. Now “Mac OS X cannot start up from this disk”. (and cannot install to this disk!)

I have a mid-2009 macbook pro, and the original 10.6.8 installer DVD that it came with. I booted up in recovery mode, and erased the HD (whether or not that was a good idea). My intention was to get ...
0
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2answers
70 views

MacBook Pro not booting, lost partition

I have a big issue with my MacBook Pro (OS X 10.10.4). I tried to enable yesterday the TRIM on my SSD disk (a Crucial I replaced myself). Everything was working fine since months but after restarting ...
2
votes
1answer
290 views

Boot Camp partition broken and can't be repaired in OS X 10.10.4

Suddenly my Boot Camp partition vanished: not visible in Finder, not visible on startup. In Disk Utility I can see the volume, but it's broken (verification log): Verifying volume "disk0s4" Verifying ...
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0answers
27 views

My LaCie Thunderbolt Big 2 is not showing on my desktop but it is showing in disk utility

I can't get access to my 6TB raid 1 (well it's suppose to be a raid one and some tech told me it sounds like it is striped but I swear I set it up as a raid 1). It is not showing on the desktop. But ...
0
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1answer
26 views

How to reformat a USB to not be a bootable operating system

I recently created a bootable USB from a .img file, here's what the USB looks like: And this is what it looks like in Disk Utility: Is there a way to reformat this USB to just store files?
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1answer
35 views

Wiping my New MacBook Pro after Using Command Q to Stop Migration

Got my new MB pro mid-2014 yesterday. Began migrating over wi-fi only to learn that it will take 14 hours that I don't have. After 45 minutes I halted on both computers using command Q. My ...
1
vote
1answer
6k 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 ...
1
vote
1answer
889 views

Is Disk Utility's “Repair Disk” a viable TRIM solution for Mac OS X Yosemite?

I'm upgrading a 2010 Macbook with an Intel 730 SSD. Since Trim Enabler is still available but more risk, I'm trying to get by with just Disk Utility. My question was prompted by this hint which ...
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1answer
1k 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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1answer
154 views

Why does Disk Utility show “Macintosh HD” on both Logical Volume Group and the volume underneath?

After performing a clean install of Yosemite (erasing the entire disk using disk utility during installation), the original name of the disk (APPLE HDD HTS547575A9E384 Media) turned out to be ...
3
votes
6answers
23k 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 ...
3
votes
3answers
1k views

Erasing partition doesn't give me free diskspace

I'm using a Macbook Air and until today I had two partitions on it (not counting the restore partition). I had my OSX partition and an Ubuntu partition. As I don't use Ubuntu anymore, I decided to ...
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0answers
45 views

Corrupt EFI Partition or Error b/c of Encryption? & Ghost Partition

I have a 2012 Mac Mini Server with two internal SSDs. Until recently, I had Mt. Lion installed on one of the SSDs, as my only boot drive, and used the other, rarely, for file storage. I created a ...
1
vote
1answer
46 views

Trying to restore Time Machine. Lost boot disk

I just bought a new Macbook Air after giving mine to my wife. Before gifting the old laptop I created a Time Machine backup. Now that I have my new MBAir, I went into Apple+R and chose to restore ...
13
votes
4answers
20k 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 ...
1
vote
1answer
27 views

How to expand partition into free space that lies before it

I would like to expand my "journal" partition to include the free space that lies (logically) before it on the drive. How can I do this without losing the data in "journal". I have a few more ...
0
votes
1answer
47 views

Issue with burning Linux .iso file using Disk Utility

I'm trying to create a Linux installation drive. I have an empty hard drive (MS-DOS format), and I already dragged the .iso file to the sidebar in the Disk Utility app. However when I press it the ...
0
votes
2answers
89 views

Problem with permissions

on my Lion Server I have noticed that the permissions for certain folders seem to be screwed up. When I look at the Get Info for the folder I see strange things in the permissions section. There are ...
0
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1answer
27 views

Disk issues on reboot [duplicate]

I have a rMBP (Mid 2012) that is having disk issues. When verifying the disk, I get three different errors: Incorrect number of file hard links Invalid first link in hard link chain Invalid ...
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0answers
272 views

Prohibitory sign on Mac startup running Yosemite

I used disk utility today on my MacBook Pro running Yosemite to create a bootable USB. I don't recall touching the hard drive of my MacBook Pro at all. After I finished the process, I went onto Google ...
11
votes
4answers
32k 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 ...
0
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1answer
67 views

Backing up Macintosh HD via Disk Utility (error -5344)

I am trying to backup the Macintosh HD, to my external hard drive via disk utility. I created a blank image and tried to restored my MacintoshHD to that image, but the error pops up, "Restore Failure: ...
1
vote
1answer
159 views

Macbook SSD Formatting Problem

I just got my Macbook here, and I got a USB with Yosemite 10.10. I opened up the Macbook, took out the old one, and put the SSD inside. My SSD fits perfectly (Samsung SSD 850 EVO 250GB). Then I ...
0
votes
1answer
58 views

System Formatter Failed While Erasing External Hard Drive Mac

I have been trying to erase my external Hard Drive "My Passport", however there was a problem and then the Hard Drive disappeared from the Desktop and could't be found. Only Disk Utility would see it ...
1
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0answers
47 views

Boot stuck at Prohibitory screen

I'm using Macbook Pro 2012 running Mac OS X 10.10.3 and earlier today, I was trying to install Linux on a USB drive through Terminal. I first converted the format with this: hdiutil convert -format ...
1
vote
1answer
41 views

Replaced OWC Mercury Accelsior E2 that I am using as a start up disk and it keeps disappearing

OWC replaced my Mercury Accelsior E2 because it stopped being recognized on my computer. They said the old one checked out ok even though I did their tests at home before I sent it in. When trying to ...
0
votes
3answers
4k views

How do I load the DiskManagement framework in single user mode?

From single-user mode in OS X 10.5, I want to run diskutil repairPermissions / but I get an error: Unable to run because unable to use the DiskManagement framework ... Is there a way to load the ...
1
vote
2answers
371 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 ...
0
votes
1answer
20 views

How can I reformat a USB

I used by USB to add as iso file into it. sudo dd bs=4m if=my.iso of=/dev/disk1 Now I want to get the USB back to normal. but the erase button in Disk Utility is disabled. How can I reformat this
3
votes
3answers
118 views

New securely erased drive not empty according to Disk Utility

Erased 32GB USB flash storage with Disk Utility's "Secure Erase" feature, one pass of zeros. Disk Utility now reports that there is only 26GB of my drive available. Not sure what is going on here, but ...
3
votes
2answers
2k 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.
2
votes
1answer
114 views

Accidentally used dd on my main OSX drive

I've made a bit of a balls up... When attempting to create a bootable Ubuntu usb drive I accidentally ran dd on my main system drive :( sudo dd if=/path/to/image.img of=/dev/rdisk1 bs=1m I ...
0
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1answer
180 views

Disk Utility Weirdness: Macintosh HD Cannot Be Repaired But Then Has No Problems?

Earlier today, I decided to clean up my hard drive of extraneous files and other materials that might be taking up space. After doing some looking around, I found an application, OnyX, that was ...
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2answers
295 views

How do I repartition my Mac to get rid of my dual boot setup?

I setup dual boot on my Mac (with Ubuntu) and want to get rid of it. The Disk Util GUI shows me: However attempting to remove the disk0s4 or disk0s5 partitions results in: Could not unmount ...
2
votes
2answers
40k 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 ...
2
votes
2answers
75 views

Split Macintosh HD into 3

At the moment I have 1 250GB partition on my mac (Macintosh HD). What I want to do is split my hard drive into 3 partitions. This is because I want to dual boot with Windows 8.1 and make a reserve ...
0
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2answers
34 views

Unable to be Repaired & Further Problems

I'll start off with some information about my USB. I use a SeaGate external hard drive USB with 1 TB. About ~250 gb of it is partitioned and formatted to create a Time-Machine compatible partition. ...