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

learn more… | top users | synonyms

1
vote
1answer
50 views

Bootcamp Partition Creation Failure

I wanted to install Windows on my 2011 Macbook Air running 10.8. I had approximately 40 GB of a 120 GB hard drive free and I set Bootcamp to create a 20 GB partition for Windows. Halfway through the ...
0
votes
1answer
5k views

External HDD can be seen in Disk Utility but not in Finder

I've been using my external HDD a lot of times before on my Macbook Pro 13" OS X version 10.9.5, but it doesn't seem to appear in my Finder anymore. It can be seen in Disk Utility, though. Can anyone ...
0
votes
1answer
376 views

Disk Utility not letting me partition my SSD or modify the current ones

Just yesterday I finally got my hands on a MacBook Pro in which I was planning to install Ubuntu and Windows aside from OS X for studying purposes. I was barely beginning by partitioning the disk, or ...
2
votes
3answers
5k views

partition map check failed because no slices were found

I own an early 2011 MacBook Pro running Mac OS X Mavericks. Recently, I tried to make 50 GB partition using Disk Utility but the whole process didn't complete, and I had to restart the system as it ...
0
votes
1answer
63 views

Mac Encrypted HDD Please help!

Hi everyone I have encrypted a partition of an external hard drive from the mac desktop. I pressed that key button then pressed memorable and it changed my entire password unknowingly. I need help. ...
1
vote
1answer
117 views

Flashing question mark, low hard drive space

When I booted my Mac last night I got a flashing folder against a gray background. The computer started fine this morning, but when I closed the lid and opened it up again I had to reboot, and now ...
8
votes
3answers
1k views

How much data has been written to my SSD over its lifetime?

Is there a Terminal command which will show me how many GB has been written to my SSD through the whole lifetime of the disk? I'm asking because I want to find out how many cycles have been done. SSD ...
1
vote
1answer
436 views

Remove Bootcamp when Boot Camp Assist will not

I purchased an iMac from a buddy and recently upgraded to Yosemite so I am learning as I go about Macs. However, I decided I wanted it to be quicker so I purchased an OWC SSD to install as a primary ...
3
votes
1answer
187 views

re expand a partitioned disk

The internal disk of my Mac book pro is partitioned as follows: % diskutil list /dev/disk0 #: TYPE NAME SIZE IDENTIFIER 0: ...
0
votes
1answer
233 views

Macintosh HD disappeared from finder after “disk damaged and cannot be repaired”

I have a MacPro 13.3 Inch mid2011 with 500GB storage and recently while performing a Mac update, it froze and was still stuck on a grey screen even after multiple restart attempts. I finally tried ...
2
votes
1answer
4k views

How to reformat/install new SSD on MBP late2010 using OS X Internet Recovery

I had been saving some money to buy an SSD and finally I did. My old HDDs motor shut down so I had to replace it. I put it in the macbook all good but it isnt recognized by the system as a hard drive ...
0
votes
1answer
466 views

Equivalents for genisoimage and qemu-img on Ubuntu

How do I achieve the same result on OS X 10.9 as I do on Ubuntu with commands: $ genisoimage -output init.iso -volid cidata -joliet -rock user-data meta-data and $ qemu-img convert -O raw disk.img ...
3
votes
5answers
9k 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 ...
0
votes
2answers
77 views

Created a second OS X partition, erased the first, now can't delete old partition

I bought a secondhand macbook pro (early 2011). It was running Yosemite, but I wanted to do a fresh install, as initially I didn't have the password. I created a 2nd partition and installed a clean ...
3
votes
3answers
33k views

OS X Yosemite installation error: File system verify or repair failed

My Mac has been running fine until I decided to upgrade to OS X 10.10, Yosemite. When it is installing I get the message: File system verify or repair failed. I clicked the restart option to ...
2
votes
3answers
12k views

Changing a Volume's “Device / Media Name”

I know a Mac volume can be renamed... obviously. But if you look at the output of diskutil you will see that a volume also has a "device name" that corresponds to the name it was given when it was ...
0
votes
0answers
842 views

Resizing and moving OSX partitions in Disk Utility

So, I have a Mac Mini with a 160GB drive (it's an old model but it's only for testing). It had 4 versions of OSX on it but one needed more space so I removed the oldest version (Lion) and want to keep ...
0
votes
1answer
1k views

diskutil eraseDisk results in Error: 12: POSIX reports: Cannot allocate memory

I'm trying to format my usb drive that is partitioned with FAT32 by the following command in Terminal: $ diskutil eraseDisk JHFS+ UntitledUFS disk1 However, I get this output: Started erase on ...
3
votes
4answers
2k views

Why does RAID 1 “Mirroring not provide performance improvements”?

I have always used Software RAIDs, either Apple-provided, or via SoftRAID, etc. I am about to re-zhuzh my arrays and decided to do a little research beforehand… and On Apple's site, there is a ...
0
votes
2answers
54 views

Resizing Partitions

I cannot resize the HD of a new Mac Mini. The Mac HD shows 700+ GB on one partition with Yosemite on it and another partition of 200+ GB named "Free Space" and I cannot figure out how it got there. ...
1
vote
2answers
513 views

Orphaned inodes in SSD in MacBook Pro Early 2011

I have a Macbook Pro 15″ Early 2011. Last year I changed the disk to put a new Samsung SSD (Evo). Recently my computer was really slow. I rebooted on the recovery partition, and tested my disk with ...
0
votes
1answer
101 views

I'm not able to re-size a HD Partition to utilize all its free space, how can I fix this?

I've seen a couple of questions on the exchange that are similar to the issues I am having. But I haven't been able to get things to work referencing those issues. I am ultimately looking to install ...
1
vote
1answer
2k views

diskutil shows Macintosh HD is missing (with Recovery HD occupying the entire space)

So yesterday I managed to screw up my iMac 2012 (with Fusion Drive) by installing the Mac OS X 10.10.2 update... The installation stalled and when I tried to restore from an external drive using Time ...
3
votes
2answers
6k views

I think I messed up the Fusion Drive on my 1TB iMac (with BootCamp)

this is a somewhat similar post to this one (Can't create partition on free space with Disk Utility) but not quite... It started with me creating a BootCamp partition (around 145 GB) for Windows ...
1
vote
1answer
55 views

Free Space Won't Delete [duplicate]

I am running OSX Yosemite. I had free space on my partition, (see picture below) but now it wont delete. I change the format to Mac OS Extended (Journaled), and then when I hit the " + " button it ...
1
vote
3answers
831 views

Clear free space in Disk Utility

So I recently removed Windows 7 from my iMac, but Bootcamp didn't let me do it. I used Disk Utility instead. The old Windows 7 partition now shows up as free space. I want to reinstall Windows 7 again ...
0
votes
0answers
53 views

Change write permissions on internal HD outside of OS

I have a late 2009 iMac with a 1TB internal HD. I am unable to boot the OS however when running disk utility, through target boot and booting into an external HD, I am unable to repair, erase, ...
0
votes
2answers
748 views

Unable to shrink a partition in osx 10.10

Hi, I installed windows using bootcamp, but i made the mistake to make the bootcamp only 20gb, so i want to expand it. I found a way to do so, but firstly i need to shrink my other partition - ...
0
votes
0answers
118 views

USB key/disk not identified as a storage device

I have a 64GB USB key that I suddenly can do nothing with...I've tried both Mac and Windows diagnostics, as described below. At this stage I don't mind losing its data (99% of which was recently ...
3
votes
3answers
4k views

Yosemite Disk Utility: You may only split this volume in two

I just upgraded to 10.10- Yosemite. I have an external 4TB hard drive. These are the problems I see with Disk Utility: No more than two partitions are allowed. Changing the partition size I can ...
2
votes
2answers
402 views

Flashing folder at start up, all recommended troubleshooting has failed

I really hope someone might be able to help with this cause I am getting frustrated beyond belief. I have a MacBook Pro with Mavericks OS X 10.9. About a week ago it crashed while I was printing, ...
1
vote
1answer
296 views

Not possible to create a sparsebundle image on a SMB mounted Volume

I'm trying to create a sparse bundle image from Disk Utility directly on my NAS (through a mounted smb volume): I then get the following error after a few seconds: Creating a sparseimage the ...
1
vote
1answer
2k views

What does “EFI system partition couldn't be created” mean?

When trying to click "Repair Disk" on an external hard drive from Disk Utility, I got the following error message: ... Repairing the EFI system partition's file system Updating boot support ...
0
votes
2answers
2k views

Partition issues after deleting Core Storage Logical Volume Group. Everything prompts an unmount error. HELP!

I followed the instructions on this link (last answer) to delete the Core Storage Logical Volume Group via terminal while pressing Cmd+R during startup. These are the functions I used in terminal: ...
2
votes
4answers
28k views

Restore Macintosh HD to its original partition configuration

I seem to have badly botched a Boot Camp installation of Windows 8.1. I used Boot Camp Assistant to create a 200 GB BOOTCAMP partition on my 1 TB Fusion Drive. I then rebooted and failed to install ...
0
votes
1answer
125 views

How do I resize an ex-CoreStorage volume?

I've got a Macbook Pro Retina (with the PCIe drive ‘blade’, instead of a traditional 2.5" laptop drive). I've recently upgraded the internal drive from 500GB to 1TB, and dd'd the old drive over the ...
1
vote
1answer
532 views

Accidently deleted some small sized partitions when installing WIndows(Bootcamp). OSX Partition wont boot

I tried to install Windows 8 into my Mac via Bootcamp. I booted into the Windows 8 Installer and had issues formatting the drive that I partitioned for the OS. Like an idiot, I deleted all of the ...
4
votes
1answer
4k views

Can't make more than two partitions

I want to multiboot my MacBook Pro, I'm trying to make partitions but in Disk Utility I can't make my partitions, only can divide by 2? Why? It's a normal SSD not a fusion drive (SSD+HD). Now I'm ...
0
votes
1answer
1k views

USB pendrive/disk formatting clarification

I have three doubts regarding USB pendrive formatting. Is there is any simple/quick way to format the USB pendrive from MacBook Pro? Now, I am doing this by Applications/Utilities/Disk Utility -> ...
0
votes
0answers
21 views

How do I repair an encrypted sparse disk image from the command line?

I have tried: hdiutil repairVolume my.dmg.sparseimage But I get the error: Ownership of the affected disk is required The sparseimage I am trying to repair is owned by me, and I have R/W ...
2
votes
5answers
24k views

How do I fix my SSD after installing Yosemite and Enabling TRIM? No boot & can't erase

I recently upgraded to Yosemite, enabled FileVault and foolishly enabled TRIM (had no idea it wasn't supported). Upon restart, my machine gets the grey screen with the crossed-out circle of death. ...
0
votes
1answer
33 views

disk become empty after delete a large file

I have a 2T mobile disk with the format of NTFS. I store 1T files on it, including a large file with the size of 260G. After I delete the large file, all the file was gone. I remount the disk again ...
0
votes
0answers
236 views

Error: -69874: Couldn't modify partition map

I would like to format my usb drive. Disk Utility returns 'Couldn't modify partition map' I run cmd + s fsck -fy. It did not work.
4
votes
1answer
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 ...
1
vote
1answer
258 views

How can I reconfigure the RAID settings on a Maxtor OneTouch III?

I have a 1TB Maxtor OneTouch III. This is the drive that comes with two 500GB disks and software to configure RAID 0 (mirroring) with 500GB of storage, or full use of both disks for 1TB of storage. ...
1
vote
2answers
2k views

Disk Utility vs Carbon Copy Cloner - How to clone your drive with Apple's built-in app

What is the point of using commercial apps like Carbon Copy Cloner when disk utility can also clone your drives? This article here ...
4
votes
1answer
6k views

OS X Yosemite Hard Disk Errors even after Repairing them

Basically, I do a lot of C programming (for class) so I use gcc a lot on my mac. Recently since two days, whenever I ran it, the entire computer is getting frozen, and a force restart is necessary to ...
1
vote
0answers
206 views

Why does hdiutil fail on symlinks when creaing an image of a Time Machine backup?

I am trying to create a compressed disk image of a Time Machine backup (that is stored on an external HDD) on Yosemite. hdiutil fails on the first symlink it comes across. Before the failure, there ...
0
votes
0answers
409 views

WD My Book Media shows up in diskutil, but doesn't mount or show up in Disk Utility

Initially this drive was connected (via FireWire) to my wife's Mac (still running OS X 10.7), but she it would not mount any more and she asked me to look at it. After reading suggestions on-line, I ...
1
vote
2answers
1k views

how do I “un-partition” my MACINTOSH HD into one big hard drive?

So I was derping around on my computer (it has a 250 gigabyte hard drive) and thought,"hmm I wonder what happens if I partition off 75 gigs of this". believe it or not, it partitioned off 75 gigabytes ...