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1 answer
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Can the GUID disk signature be changed without reformatting a disk partition/drive?

After recently having some issues with an 8TB Seagate drive, I bought a new replacement to backup, and realised I have this dock sitting here with dual bays that can clone a disk far faster than any ...
Lee Lawrence's user avatar
2 votes
1 answer
88 views

Troubleshooting GUID partition "FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFF" [duplicate]

Running a Mac Pro 2013 with macOS Catalina. Looking to change the GUID type from FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF to 7C3457EF-0000-11AA-AA11-00306543ECAC. I've been browsing through various ...
cheoso's user avatar
  • 23
0 votes
2 answers
600 views

How can I do a GPT (Guid Partition Table) sector raw backup with `dd` like in a UNIX/Linux-MBR fashion?

I want to "raw copy" with dd the critical GPT (~ Guid Partition Scheme) bytes of my computer's main hard drive, to an arbitrary file. I tried to do the equivalent MBR/Unix/Linux in my Mac (...
nostromo's user avatar
  • 197
2 votes
2 answers
1k views

Inaccessible APFS Partition - no gpt scheme

In an attempt to recover a different external drive altogether, my drive "Libraries" was compromised. Just for it being connected at the same time. I'll be sure to disconnect drives I'm not ...
CyX SenZe's user avatar
1 vote
0 answers
223 views

Tried to install Kali Linux and now I can't access macOS anymore

It has been 3 days, I was trying to recover it but now I am out of options. I've tried installing Kali Linux on my Mac as a dual boot with a Linux partition of 20.5 GB inside my 500GB SSD and 1GB of ...
Yuouo's user avatar
  • 11
1 vote
1 answer
1k views

Error: -69519 when resizing partition of apfs container scheme

I am trying to resize the partition disk0s2 in my Mac. My diskutil list shows: /dev/disk0 (internal, physical): #: TYPE NAME SIZE IDENTIFIER 0: ...
Gustavomoty's user avatar
0 votes
0 answers
583 views

How do i repair a corrupt drive without losing data

I was copying data from an old ds112 Synology hard drive to a new install on a ds112 due to board failure of the other one. I have the old drive in a caddy and was successfully copying data when I ...
Aaron Durber's user avatar
0 votes
0 answers
161 views

Restore a partition on an external drive after enclosure failure

I had a very freak electrical accident with my iMac 5K a few weeks ago. One of my external drives (my backup drive) shorted out and would no longer mount. I decided to buy an 3.5" enclosure as I ...
Tomasch's user avatar
0 votes
0 answers
88 views

Partition type FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF, drive unmountable How do I fix this?

I started having this issue when I tried to swap my sshd for an ssd. My caddy was broken so I tired booting into bootcamp to run disk cloning software. (Seagate backup time machine disk failed on me....
Iridium62's user avatar
2 votes
1 answer
911 views

How to fix FDISK_partition scheme after repartitioning a larger space for bootcamp

I have a Mac that is running Mojave, and yesterday I was trying to repartition the disk so I could get more space on my Windows partition for bootcamp. In the process, the Windows folder only appeared ...
jacobbarker's user avatar
0 votes
0 answers
361 views

Is it possible to repair a Mac external hard drive's partition table, without access to a Mac?

I tried to create an NTFS partition on an HFS+ formatted Mac external hard drive, from within Windows. This hosed the GUID table. In order to try to recover the files, I had to turn off journaling, ...
spillthrill's user avatar
1 vote
1 answer
257 views

Cant install bootcamp in MBR after internal SSD upgrade

I upgraded internal kSSD on my mac (MBP-2013) via Carbon Copy Cloner. OSX loads fine, but for some reason I cannot boot into Windows that I have installed on external USB in MBR mode. Prior to ...
Stpn's user avatar
  • 141
1 vote
0 answers
66 views

How can I recover my external drive's partition table?

I have an old WD MyBook Ext Drive and I couldn't access the greyed out sub-partition in DiskUtility. I was trying to fix it with various Terminal commands relating to GPT and somehow I managed to mess ...
user7507965's user avatar
1 vote
0 answers
515 views

EFI missing, Question folder appears, Mac SSD appears and disappears, what do I do?

Setup Macbook Pro retina 13 A1502, SSD 128Gb Running Yosemite, but currently doing the update for high sierra. Problem: Question marked folder appear after I left it for 2 days, battery run out (left ...
Rennoracle's user avatar
1 vote
1 answer
2k views

How to fix CoreStorage not mounting? Broken GPT, GUID, volume etc?

I have an external hard drive with two partitions, each one formatted as "OS X Extended (Journaled, Encrypted)". The second partition mounts and asks for a password, but the first one does not. The ...
AGG's user avatar
  • 11
1 vote
1 answer
552 views

Making Conflicting UIDs across a LAN of MacOS and Linux hosts Consistent

I have an expanding network and while I have the long term goal of eventually implementing Active Directory hosted on a QNAP NAS. However, in the meantime I have the issue of where my MacOS machines ...
Darf Nader's user avatar
1 vote
1 answer
2k views

MacOS partition shows up as FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF (Mojave)

I suspect this this may be a duplicate, but I'm not sure what I should do considering almost everyone else has another macOS version or other partition size and I'm not sure how to generalize another ...
N3ur0's user avatar
  • 13
5 votes
1 answer
2k views

I can no longer boot into macOS after resizing my bootcamp partition in EaseUS

I tried to enlarge the bootcamp windows 10 partition by 17gb. I went to disk utility on my mac, resized the mac's partition to smaller leaving 17-18gb of free space, then booted up the windows in ...
user2923339's user avatar
4 votes
0 answers
311 views

Recover data from external hard drive partition Mac OS X

A couple of weeks ago, I dropped my external drive while a program was writing data to it. The drive seems to spin up fine, without beeps/scratches. The drive also has EFI and Recovery partitions. One ...
KDhimroab's user avatar
3 votes
0 answers
439 views

lost Mac OS X partition after resizing bootcamp

Recently I tried to resize my bootcamp partition. I first resized the Mac osx partition to a smaller one with diskutility and appended this space to the bootcamp partition from within windows 10 (with ...
Renier Braam's user avatar
1 vote
1 answer
712 views

How to recover trashed GUID partition table?

I did something stupid. I ran (something like) diskutil partitionDisk /dev/disk2 GPT HFS+ newdisk against the wrong disk. It was one of those moments where you realize what you've done, as you're ...
voices's user avatar
  • 2,229
27 votes
1 answer
58k views

How to choose GUID with High Sierra's Disk Utility?

Most often USB flash drives on the market are pre-partitioned under (Windows) Master Boot Record. Until El Capitan a special widget in Disk Utility made it possible to set the partition type to GUID. ...
Calaf's user avatar
  • 4,369
2 votes
1 answer
541 views

Recovering "Damaged" Files on External USB Drive: GUID, HFS (can not open files)

I had some files on an old thumb-drive, and recently I was going through and discovered that all/most of the files were no longer readable by any of my macs. I seam to remember having similar problems ...
user avatar
2 votes
1 answer
1k views

Corrupted GUID partition table on secondary hard drive

I have a Hackintosh computer, with a secondary hard drive installed with a bunch of data on it. I was trying to partition off part of the secondary hard drive to install Windows so I could dual boot, ...
Wassilleyert's user avatar
6 votes
0 answers
4k views

Whats wrong if 'Invalid BS_jmpBoot in boot block: 000000'

I have a corrupted partition and upon trying to repair it with disk utility it gives the error Invalid BS_jmpBoot in boot block: 000000 Several postings on the internet describe this problem related ...
bomben's user avatar
  • 1,093
1 vote
1 answer
945 views

Creating encrypted disk image passphrase in Keychain, and strange GUID account

When a user persists an encrypted disk (or disk image) passphrase in the Keychain (e.g via Disk Utility as shown here, https://apple.stackexchange.com/a/229309/5392 or when setting up an encrypted ...
Lloeki's user avatar
  • 1,856
2 votes
0 answers
437 views

Macbook can't read Macintosh HD

I use a late 2013 macbook pro 13 inch retina display. I tried formatting my internal ssd hard drive (macintosh HD) after it started freezing forever whenever I tried to log in. I tried all the ...
Loruo Josiah's user avatar
0 votes
1 answer
175 views

How to save data from broken GPT, GUID and unmountable, no type volumes?

I have a Macbook Pro mid 2012 and 750GB hard drive. I tried to delete Windows partition on the hard disk and now I can't access my main Mac partition (disk index 2) anymore. It shows something like "...
memyana's user avatar
3 votes
1 answer
899 views

Recover Corrupt SSHD

I had an old 2011 13" MPB with a 250 GB Samsung Evo 840 SSD and, using the OWC expansion bay mod, a 1 TB Seagate SSHD. The SSD was the boot drive and the SSHD was just for Time Machine backups, file ...
Jon B's user avatar
  • 127
1 vote
0 answers
55 views

External HD changed partition map

Apparently my external HD went crazy (I've been using it without problem for a long time) and decided to change partition scheme from GUID to FDisk (look at disk1) but my data remains as HFS+ (disk1s2)...
Luis Vera's user avatar
  • 173
2 votes
0 answers
621 views

MBP SSD Deep Formatting Problem - Will Format as FAT32 but fails as HFS+

My MBP SSD crapped out the other day, I'm pretty sure it was user error (too full). I was able to run my emergency OS via external drive and collect my files, but had difficulty deleting them from my ...
user198449's user avatar
1 vote
1 answer
715 views

Time machine: include external FAT drive

I am trying to backup an external FAT drive with time machine on a new WD HFS+ formatted hard drive, and I've read it is possible. However, I find it in the excluded list, and I cannot remove it ...
senseiwa's user avatar
  • 227
0 votes
1 answer
2k views

How do I install Windows on separate disk using GPT/EFI and BootCamp?

I have a Late 2012 27 inches iMac with an internal HDD (that has a Macintosh HD partition, an EFI partition and a Recovery partition) and an SSD. I installed Windows 10 on using BootCamp Assistant; ...
Manchineel's user avatar
2 votes
1 answer
519 views

How to create a new partition on FileVault disk on MacOS

I have a 500GB disk on MacOS encrypted with FileVault 2. I have successfully resized the disk to 250GB. Now I want to create another partition to install another MacOS on the 250GB free-space of the ...
L N's user avatar
  • 527
13 votes
2 answers
36k views

How to fix broken GPT, GUID and unmountable, no type volumes?

I have a Macbook Pro with retina, Yosemite and 500GB hard drive. I tried to install Windows using Bootcamp and accidentally deleted a partition, now my Mac cannot boot anymore. This is the output from ...
L N's user avatar
  • 527
1 vote
1 answer
70 views

Unable to access neither Partition Layout nor Option tab in Partition tab on Disk Utility

I have a problem that I cannot select Option tab in Partition tab as shown in above screenshot. I wanted to convert my external hard disk to GUID partition table. Thank you in advance for your help.
21Tech's user avatar
  • 11
4 votes
2 answers
21k views

Rebuild partition table on external HDD - not writable

I have an external hard drive formatted with 3 HFS+ partitions. To cut a long story short I had it connected to a Windows PC and accidentally started formatting the drive to NTFS. As soon as I ...
dobestar's user avatar
  • 141
0 votes
1 answer
2k views

How do I roll back from Yosemite to Mountain Lion without Internet Recovery after erasing my hard disk?

I erased my MacBook Air hard drive - which came with Yosemite OS X - because I wanted to roll back to Mountain Lion (OS X 10.8), since Yosemite was giving me problems with my files from the previous ...
Tofa's user avatar
  • 1
0 votes
2 answers
448 views

Can I run a disc image of a cloned Tiger or Leopard PPC drive on a modern Intel Mac via virtualization software?

I have a PowerMac G5 PPC running Tiger and an old, white, Santa Rosa MacBook running Leopard. If I create cloned disc images of these OS drives, will I be able to run them in VMWare Fusion/Parallels/...
Kerlix's user avatar
  • 1,470
0 votes
1 answer
343 views

Time Machine Changed My External Hard Drive's to MBR and now I can't access it!

On Yosemite, I was using Bootcamp to install Windows on a part of my internal hard drive. When, bootcamp was finished (before booting into Windows), Time Machine popped up and asked me if I wanted to ...
Kelley Chambers's user avatar
1 vote
1 answer
1k views

Why is a hard drive not readable anymore after removing it from the Mac?

I have a mid 2010 27" iMac. Until this evening it had an SSD (primary drive with OS X Mavericks installation on it) and a HDD as second drive. The HDD is a Western Digital I built into the iMac in ...
p13n's user avatar
  • 140
0 votes
1 answer
12k views

How to fix broken GPT, GUID and unmountable and without type volumes?

I have Macbook pro with mavericks and 512GB SSD i accidentally deleted a partition and suddenly my mac could not boot any more and after i tried to do something with disk utility this is gpt -r show ...
alsadk's user avatar
  • 103
0 votes
1 answer
66 views

GUID partition scheme

If I try to change a partition scheme of a 4 partition HDD from Apple to GUID, iPartition warns me that 'system partition' will be erased. What does that mean? Thanks.
Carlos Santiago's user avatar
2 votes
0 answers
46 views

Recovering reformatted partition

I have an external drive that had a single HFS+ partition (GPT). It was accidentally formatted. How can I recover the lost partition? I "know" the old partition map which (coincidentally?) is the same ...
Alexandros Chalatsis's user avatar
1 vote
1 answer
5k views

HD accidentally reformatted to MBR, how to get back to GUID?

So in trying to create an MBR partition of my hard drive which I could then use to boot a solaris-derivative OS using rEFIt, I messed up. Rather than a hard drive with a primary GUID partition map ...
Nathaniel Gentile's user avatar
5 votes
1 answer
14k views

When is the GUID partition table (GPT) preferred over Apple partition map (APM) for external drives?

I have seagate external portable hard-drive 1 TB, and I will be using with following Mac's. 13" White MacBook (Intel Core 2 Duo) running Snow Leopard 13" MacBook Air (Intel Core i5) running Lion iMac ...
I-M-JM's user avatar
  • 1,546