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76 votes

External drive does not mount after plug off without eject

SOLVED. Had this problem today. OLD external drive, had its own power source, plugged into a surge protector. I hit the power button on the surge protector when I was unplugging something else, and ...
stereof's user avatar
  • 761
69 votes

External drive does not mount after plug off without eject

I'd recommend checking if fsck is holding your disk hostage upon connection. This was it for me. Running ps aux | grep fsck revealed: root 2587 7.3 0.1 4363584 21780 ?? U 10:...
Ariel Allon's user avatar
  • 1,896
19 votes

How do I get detailed SMART disk information on OS X (Mavericks or later)

Extending on Lee Joramo's excellent answer you can install the GSmartControl GUI on top of smartmontools. It comes in a Homebrew tap. So the procedure is: brew install smartmontools brew install ...
n1000's user avatar
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14 votes
Accepted

macOS partition startup Volume type FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF

The proper GUID of APFS partitions is 7C3457EF-0000-11AA-AA11-00306543ECAC. The default pMBR was replaced with an old-style MBR, probably by the Linux installation! Your boot system (in Internet ...
klanomath's user avatar
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14 votes
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dd on Catalina gives "Permission denied" error even after grant it Full Disk Access in Security and Privacy

My bad. If this happens to you, you might want to check the switch on your SD card to see if it is set to read-only. :)
Alex Ryan's user avatar
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11 votes
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How to create a read-only RAM disk on macOS from the command line?

Get the device number of the RAM disk: diskutil list (e.g. disk3) Add some content to the RAM disk 😉. Unmount the volume: diskutil umount disk3 Mount the RAM disk read-only: diskutil mount readOnly /...
klanomath's user avatar
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9 votes
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How can I create a bootable drive for ArchLInux on macOS?

There is no command in macOS to format a partition to use a linux file system. In other words, there is no equivalent for the Arch Linux mkfs.ext4 command. There are many possible solutions to this ...
David Anderson's user avatar
9 votes
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All of a sudden can't open .dmg files on Monterey

I fixed it! - I recently ran a command to stop receiving annoying messages about umounted drives: sudo defaults write /Library/Preferences/SystemConfiguration/com.apple.DiskArbitration....
Hackeron's user avatar
  • 266
8 votes
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How to make remove free space and make APFS container take it up

This answer was tested using Big Sur (macOS 11.0.1). For Catalina, set this question. Boot to Big Sur. Close all applications. Open the Terminal application. You can create a new APFS container. ...
David Anderson's user avatar
5 votes
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Format external HFS disk without ESP

You can repartition the disk with gpt and format the partition with newfs_hfs: Open Terminal.app and to get an overview enter: diskutil list Get the partition table of the disk in question (below I ...
klanomath's user avatar
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5 votes

How do I get detailed SMART disk information on OS X (Mavericks or later)

Quite new and compatible with MacOS Sierra, Yosemite and El Capitan option: Get native precompiled package from https://sourceforge.net/projects/smartmontools/ Install it, open Terminal and run: ...
Arunas Bart's user avatar
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5 votes
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diskutil info disk0 shows --> Volume Name: Not applicable (no file system)

Your findings are completely normal for a physical disk like an Apple SSD. A common physical disk partitioned in macOS doesn't contain (a) file system(s) but a partition table, partitions and some ...
klanomath's user avatar
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5 votes
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I accidentally caused one of my encrypted drives to start converting into a decrypted drive. How can I stop it?

Even though it is an external drive, the encryption system being used is still FileVault. There's currently no method to cancel a decryption of the drive. You'll have to wait until the drive is fully ...
jksoegaard's user avatar
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5 votes
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How to know what the different `roles` do in `diskutil apfs` shell command

The roles are: B=Preboot (boot loader) R=Recovery V=VM (swap space) I=Installer (temporary usage) T=Backup (Time Machine) S=System D=Data U=User N=Baseband E=Update X=XART (hardware security) H=...
jksoegaard's user avatar
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4 votes

How do I get detailed SMART disk information on OS X (Mavericks or later)

Some additional information running smartctl 7.1 on macOS 10.15 (Catalina)+ Behaviour / output varies if SSD types are different, e.g. NVMe vs SATA/SATA Express NVMe MacBookPro14,3 (NVMe) 512GB ...
Terry Wang's user avatar
4 votes

Difference between "diskutil mount" and "sudo mount"

mount() is actually a system call, that means it's a C function offered by the system library (libSystem) to tell the system to mount a disk drive. It will talk to the operating system kernel and ...
Mecki's user avatar
  • 941
4 votes
Accepted

External disk does not show in "diskutil list" after premature eject, what can I do?

Reading the man page of diskutil, I found a command that I thought might provide at least some diagnostics on what was wrong: diskutil activity When you run this command, it will start monitoring ...
Julian's user avatar
  • 171
3 votes

Can´t mount encrypted external hdd after encryption was interrupted

A reboot usually un-pauses conversion, so I would try that first. Consider storing the passphrase in your keychain (even if temporarily) so that it mounts when you log in and gets going on conversion ...
bmike's user avatar
  • 238k
3 votes

How to reclaim free space partition on macOS High Sierra?

To convert an APFS container to free space you'd have to delete the container first: diskutil ap deleteContainer disk1 Then you can demote the partition to unallocated disk space with: diskutil ...
klanomath's user avatar
  • 66.6k
3 votes

How do I create an encrypted APFS volume from the command-line?

It seems that the volume was created correctly, but hdiutil attach just provides misleading output when you try to mount a disk with an encrypted volume on it. If you use -nomount and then proceed ...
Hakanai's user avatar
  • 448
3 votes
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How to resize Apple partition?

Disk Utility for macOS Sierra: Partition a physical disk using Disk Utility Please make sure to preform a backup prior to partitioning. Although a standard process, there's always an increased risk ...
user7886229's user avatar
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3 votes
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MacOS: two hard drives, one empty

It looks like your Fusion Drive got split. Apple has some instructions here explaining how to fix it. I have copied the instructions here, but they made be easier to read and more up to date at the ...
drivec's user avatar
  • 2,882
3 votes

Double Erased my 64GB flash drive, but failed both. How to fully erase it again and make it work?

Your intuition is a bit off - that's what gives you most of the troubles. After you have formatted the drive there is nothing left over - i.e. you do not have to worry about "buffer files from exfat" -...
jksoegaard's user avatar
  • 78.6k
3 votes

How to set a consistent location for drives mounted on boot?

Is there a way to set how the drives mount on boot so they are always at the same mounting location/path? You don't need to specify the order in which they boot; you use the UUID. To get the UUID ...
Allan's user avatar
  • 103k
3 votes
Accepted

How can I mount a TimeMachine Backup snapshot in the Terminal via mount_apfs?

Part 1 - the role of /Volumes/.timemachine There is a misconception about what is in /Volumes/.timemachine/<GUID>/. It contains mount points which may or may not have mounted TM snapshots. Some ...
Gilby's user avatar
  • 11.4k
2 votes

EFI system partition repair

I had a similar issue with a MacBook pPo A 1278. HDD as internal device does not boot. Connected as external USB drive -> HDD boot. Problem solved by replacing the internal SATA cable for (currently) ...
dau-d's user avatar
  • 21
2 votes

Couldn't open device

Similar problem, so I tried erasing as FAT… (can't remember the exact format) which worked. Then was able to erase again as Mac OS Extended (Journaled). I suspect my problem was that I had made the ...
Greg's user avatar
  • 131
2 votes

Why won't an fsck-declared-good volume mount?

I had same problem... fix/work-around was in Terminal do something like: mkdir /tmp/3 sudo /sbin/mount_hfs /dev/disk3s3 /tmp/3 df -h /tmp/3 Filesystem Size Used Avail Capacity iused ...
dukechem's user avatar
2 votes

Mounted drive does not show up on Disk Utility, Desktop, Finder Sidebar

A simple restart fixed the issue for some reason.
user191378's user avatar

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