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

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23
votes
5answers
35k 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 ...
5
votes
3answers
32k 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 ...
27
votes
9answers
116k views

Unable to Resize Partitions

I have recently created a partition on my macbook air running OS X 10.9, and this was to run install another OS instance (Yes, OS X 10.10 Yosemite, but that is an aside to the query I have) on it. I ...
9
votes
4answers
60k views

How can I resize a partition with Disk Utility?

I have 2 partitions, I reduced the size of one and want to expand the other to fill the now available space. How do I expand the Lion Partition into the empty grey space beneath Macintosh HD ...
3
votes
4answers
1k views

What techniques for disk, volume and file system management are possible with OS X, but troublesome within Disk Utility?

In the past, Disk Utility was the best starting point for the vast majority of disk-related tasks. As technologies within (or possible with) OS X have developed – without equal development of Disk ...
3
votes
2answers
2k views

What are the purposes and safety to enable the hidden debug menu in Disk Utility?

I'm primarily interested to know whether installation of Lion included the Recovery System. I understand you can enable extra formats and debugging in Disk Utility, using the following commands: ...
4
votes
4answers
21k views

Recovering data off of a dead hard drive

My hard drive died in my macbook and it no longer will start up. It will not mount in an external enclosure but disk utility is still reading that the hard drive is there, and I tried to repair disk ...
4
votes
1answer
9k 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 ...
3
votes
1answer
8k 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 ...
3
votes
3answers
863 views

Unable to increase partition size with subsequent blocking partition

I can't make my main Macintosh HD partition bigger. It's limited by the partition in the middle, which seems to be frozen, I can't move it down to make space for my main partition. Also I can't seem ...
2
votes
4answers
69 views

How can I find what is using the rest of my drive?

I am using a Macbook air. 64GB. My user directory has used 20.47GB Disk Utility shows 'Other' is 41.33GB and I only have 2.9GB free. What tools or command line commands can I use to find out what ...
9
votes
1answer
26k views

Create new partition in unallocated space with diskutil

I have deleted the first partition on my external HD such that it now has 100GB of free space at the beginning of the partition. I'd like to reclaim that space, but Disk Utility doesn't let me create ...
12
votes
3answers
58k views

How can I delete a partition (coreStorage logical volume?) from the Terminal?

I finally understood why Disk Utility will not change the partitions on my HDD, even though I added the most recent one myself (maybe significant: to test Yosemite DP) with it. Now I see it says it ...
8
votes
2answers
6k views

How to fix Disk Utility, About This Mac, and Finder that disagree on hard drive space usage?

Has anyone seen this issue and know how to fix it? Look at the free space reported by running "Get Info" on my hard drive (Macintosh HD) in the Finder, "About This Mac" from the Apple Menu, and Disk ...
7
votes
2answers
62k 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 ...
6
votes
1answer
14k views

Why can't I write to the last block of my SDXC card on my MBP?

I have a 64GB SanDisk SDXC memory card which I would like to use with my MacBook Pro and its SD card slot. However, I am having some trouble formatting/partitioning my SD card and I can't figure out ...
6
votes
2answers
27k views

How do I change a disk partition map scheme from MBR to GUID Partitions Table?

I just finished the huge download of Mac OS X Lion, started the installer, and now I have a problem. The installer says that I must have the GUID-Partitions Table Scheme. The problem is that when I ...
5
votes
2answers
20k views

installation stuck in a loop due to damaged HD

Right off the bat I'll admit it was stupid to jump into trying to install a new version of OS X to the only partition without having taken adequate precautions (no backups or recovery disks), but ...
3
votes
4answers
57k 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 ...
2
votes
1answer
6k 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 ...
0
votes
1answer
95 views

EFI automounts on startup

After upgrading to the newest El Capitan from 10.10. to 10.11.1 - I guess - the normally invisible EFI partition appears on the desktop as a regular volume on different machines, if I choose to show ...
12
votes
1answer
15k views

Can't ever remove partition?

Running Mountain Lion. I added a partition with Disk Utility and then had second thoughts about it. I'd like to remove the partition i created, MacSSD2 and hand over its space back to MacSSD. As you ...
3
votes
3answers
8k views

Remove “Windows” Entry from Mac Boot Loader

Background A while back, I installed Windows 8 on my MacBook Air (mid 2013 model) using Bootcamp. It never really worked, (it would freeze all the time, the WiFi would cut in and out, etc.) so I got ...
2
votes
1answer
336 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 ...
13
votes
6answers
55k views

What is the best way to clone a disk between two Macs?

What is the best way to clone a disk between two Macs? I ask this every couple years or so and every time I get the same answer. "Use Carbon Copy Cloner", they say. But the unfortunate fact is that ...
27
votes
3answers
30k 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 ...
10
votes
3answers
49k 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 ...
31
votes
4answers
75k views

How to resolve error: “Couldn't modify partition map because file system verification failed”?

I upgraded to Lion and decided I no longer want 100 GB of my drive devoted to Boot Camp, I never boot into Windows, I just use it as a VM anyways. So I deleted the boot camp partition using disk ...
18
votes
13answers
180k views

How can I repair a disk that Disk Utility says it can't repair?

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
3answers
5k views

Unable to resize Lion partition

I decided to do a clean install of Lion on a new partition, then after copying my stuff removed the old one. I'm now stuck with 100~ GB of free space and a 20 GB partition that Disk Utility won't let ...
10
votes
1answer
513 views

I know how to repair disk permissions. But… Who broke them?

One of the common Mac troubleshooting steps everyone always seems encouraged to try first is to "repair disk permissions" in Disk Utility. This process usually finds random odd problems, fixes them, ...
6
votes
2answers
4k views

What terminal command or program can list an SSD's Power On Hours?

I'm looking to script using the unix shell the retrieval of SSD (and HDD) data that disk utility shows in the information window. I'm immediately interested in the Power On Hours and Power Cycle, ...
4
votes
3answers
506 views

Copying Time Machine backup, destination takes more than original size, are hardlinks being expanded?

I'm copying the backup folder of Time Machine, but it's taking too long, the backup is 90GB and the copy already reports 160GB and there's 60% to go yet, so I suspect it's copying hardlinks as ...
1
vote
2answers
4k views

Recurring “error code -50/invalid argument” resolved by reboot, better solution sought

I'm using an old iBook G4 (PowerPC) running Tiger to serve iTunes to the house. For the past week or so, the mac boots fine, and then sometime during the day starts generating An unexpected error ...
1
vote
2answers
364 views

What's the tool that can do some actions when a file is copied?

I use Cmd+L to make a alias, and the alias has "alia" appended to the original file name. I move the link to a directory, then remove the "alias" part manually. Is there a tool that can do this kind ...
7
votes
3answers
16k views

Disk needs repaired… but it doesn't?

I've been noticing some oddities with my computer lately. Applications running slower than normal. Hanging. I decide to run Disk Utility and I get the following statement: So I do what it says and ...
6
votes
2answers
9k views

How do I recover an “invisible” OS X boot option in BootCamp (running on a 2013 MBA)?

Summary Unable to boot into the OS X partition of a 2013 MBA which dual-boots OS X and Windows 8 via BootCamp. Could "Repairing Disk" via "Disk Utility" damage the working Windows 8 partition? What ...
4
votes
1answer
1k 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 ...
3
votes
2answers
47k views

Cannot Unmount Mac OS X Base System Disk

My Mac running Lion was being slow, so I was decided to reinstall OS X. I don't have any Time Machine backups. Everything went file, but in the middle of the installation, it got stuck, and later the ...
2
votes
1answer
236 views

Repair an exFAT drive on Mac OS X after it's been improperly disconnected

Very often an exFAT external disk stops appearing in OS X. It doesn't appear in Disk Utility, Finder, diskutil list or About this Mac/System Report/USB. The only way I have found to fix it is to boot ...
2
votes
3answers
3k 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 ...
1
vote
3answers
764 views

For bad and/or marginal blocks on hard disks, can anything be more effective than a single pass of zeros?

There's a good discussion in Apple Support Communities – Disk Utility: for bad blocks on hard disks, are seven overwrites any more effective than a single pass of zeros? (2011-04-21) A highlight: ...
1
vote
1answer
8k views

How can I resize my Lion partition to fill up the unused space on the drive?

My MacBook (Late 2007) has an 80GB hard drive. I used to have a 15GB Boot Camp partition, and deleted it at some point -- but I forgot to resize my Snow Leopard partition to fill the 15GB of free ...
3
votes
1answer
299 views

Not enough storage for El Capitan; no way to free up space

I wanted to upgrade my Macbook 2008 from Yosemite to El Capitan. Unfortunately, when I downloaded it and restarted my computer, on the "select the disk on which to install" page the only location, ...
3
votes
2answers
4k 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 ...
2
votes
3answers
295 views

Completely erased my Leopard machine from another computer, how do I install an OS on it?

I started up my computer in Target Disk Mode and erased it from a friends Mac thinking that I could then install Mountain Lion without installing Snow Leopard. Do I have any way of getting my machine ...
2
votes
3answers
440 views

Exact clone of HD

I managed to broke something on my iMac's internal HD. I have now done a successful restore using DiskDrill, but just in case I want to make an exact copy of the internal HD. Not just some partition, ...
2
votes
2answers
5k views

Disk diagnostic and repair utility for Mac that works with all kinds of storage devices?

There are some nice and useful utilities for testing disks for bad blocks like MHDD, Victoria, HITACHI Drive Feature Tool etc. But these utilities have some limitations. For example, MHDD is the best ...
1
vote
3answers
20k views

USB Drive Will Not Mount, Not Listed in Disk Utilities, but Found In System Profiler

I have a Seagate FreeAgent Go drive with the optional docking station. I use it to keep files that I don't access on a regular basis and as a place to do "quick backups" of things like my Paperless ...
1
vote
1answer
333 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 ...