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24 votes
Accepted

OS volume shows as type 'FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF'

A bootable OS X partition (except the Recovery HD) either has the GUID 48465300-0000-11AA-AA11-00306543ECAC for a standard OS X partition, the GUID 53746F72-6167-11AA-AA11-00306543ECAC for a ...
klanomath's user avatar
  • 66.6k
9 votes
Accepted

APFS with external hard drives (non SSD)

APFS has no advantage over HFS+ (macOS extended) and vice versa in terms of post-mount performance when it comes to hard disks (non-SSD drives). However, macOS Sierra (10.12) or older can not access ...
Alper's user avatar
  • 4,016
8 votes

CoreStorage logic volume failed to mount

I ran into this. In my case it seems the problem was the mac wanted to run a filesystem check on it. After finding the fsck process and killing it, I could then mount the drive properly. $ ps -ef | ...
zeroimpl's user avatar
  • 181
7 votes

APFS with external hard drives (non SSD)

For HDD, if you are not going to install macOS, then use a Mac OS Extended (Journaled) or Mac OS Extended (Journaled, Encrypted) format. When using a hard drive just to store files, APFS or APFS (...
David Anderson's user avatar
3 votes
Accepted

Can't resize partition: "You can't perform this resize unless it has a booter"

Note: This answer assumes your drive is not hybrid partitioned. In other words, I assume your drive is using a GUID partitioning scheme and the Master Boot Record (MBR) table is fully protected. Also, ...
David Anderson's user avatar
3 votes

unlock macOS encrypted Volume on linux

For accessing CoreStorage encrypted volumes, you can use the freely available libfvde software on Linux: https://github.com/libyal/libfvde For APFS encrypted containers you can use either: The ...
jksoegaard's user avatar
  • 78.5k
3 votes

APFS with external hard drives (non SSD)

It would seem that one big advantage of using APFS, even on rotating drive, would be that it can take advantage of the copy-on-write technology, via the Finder or in Terminal with cp -c, thereby ...
Rick Gordon's user avatar
2 votes

Missing Space on Drive using Core Storage after Boot Camp Assistant Failure

The use of Core Storage seems to be a common denominator in problems similar to mine. I used the sudo diskutil cs revert [Logical Volume guid] command in the Terminal application to get rid of Core ...
Alan Norton's user avatar
2 votes
Accepted

I want to triple-boot Lion, El Capitan, and WIndows. Howto?

iPartition used to be the go-to tool for this kind of task, but it cannot handle Core Storage volumes, which makes it a bit limited these days. Paragon have just brought out a new Hard Disk Manager ...
Tetsujin's user avatar
  • 117k
2 votes

Expand OS X partition

The recommended method to expand Macintosh HD is to backup and remove your Windows partition with WinClone, expanding your OS X volume and restoring the Windows partition. This can also be done with ...
klanomath's user avatar
  • 66.6k
2 votes
Accepted

How to repair HFS+ partition?

The partition map is completely valid - the CoreStorage stack is messed up though. After creating a CoreStorage stack (e.g by enabling FileVault) the CoreStorage logical volume group should contain ...
klanomath's user avatar
  • 66.6k
2 votes
Accepted

iMac disk partion FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF and fusion drive unlinked

The second (and the third) partition of your internal HDD got the wrong partition types, your data probably won't be lost. If one part of a Fusion Drive (i.e. disk0s2) suddenly get a wrong partition ...
klanomath's user avatar
  • 66.6k
2 votes

Reverting a CoreStorage Volume

I ended up stumbling across the answer to my own questions (although David is right, I could have avoided it by following his steps). The guides I found all pointed to the first UUID, but it's ...
Coleman Kelly's user avatar
2 votes

How can I *unlock* a CoreStorage logical-volume without mounting it?

Click the Unlock button in the top-right of DiskWarrior and enter the password to unlock the volume
Greg's user avatar
  • 21
2 votes
Accepted

Strange virtual disk. Delete or leave?

The internal virtual disk is a Logical Volume and part of a CoreStorage Logical Volume Group. CoreStorage itself is a logical volume manager similar to Linux' LVM. An LVM is an additional abstraction ...
klanomath's user avatar
  • 66.6k
2 votes

Remove Linux partition on Mac. CoreStorage problems

By accident the OP took one command in the answer Remove Ubuntu and grow Mac partition literally and entered: gpt add -b 409640 -i 2 -s 118430560 -t 53746F72-6167-11AA-AA11-00306543ECAC /dev/disk0 ...
klanomath's user avatar
  • 66.6k
2 votes
Accepted

Where are Core Storage instructions stored?

Starting up from a core storage volume -- whether encrypted or not -- requires a non-Core-Storage volume to hold the booter file. There's some coverage of this in reference section 26.1 of the Support ...
Gordon Davisson's user avatar
2 votes
Accepted

How do I print my logical volume group UUID to file?

Note: This answer is just example code as I only have one Core Storage Volume to test against, however, if there's more then one, the awk command could be modified to accommodate accordingly. Although ...
user3439894's user avatar
  • 59.1k
2 votes

Difference between enabling Time Machine's "Encrypt Backups" option, and encrypting from Disk Utility?

The command: diskutil list my_time_machine_disk_short_name will confirm you: # my_mac:/Users/bob % diskutil list disk5 /dev/disk5 #: TYPE NAME SIZE ...
dan's user avatar
  • 12.3k
2 votes

CoreStorage logic volume failed to mount

Maybe check to see if you have any softwares running that block mounts, such as "disk arbitrator". In my case I forget to disable it, and after quitting it my disk mounted. (However, it may not show ...
Joy Jin's user avatar
  • 2,833
2 votes

Is it OK for Time Machine to take a long time to decrypt a freshly formatted encrypted disk?

I’ve had the same question, and after a bit of research (and based on my own experience) I’ve come to some conclusions: Encryption made by TimeMachine and Encryption made by disk utility is the SAME ...
KitsuneSama's user avatar
2 votes

Hard-Drive Storage size issues after partition Disk Utility

To run a whole-disk repair, you need to do it from the command-line: diskutil repairDisk /dev/disk1 Be sure to use the correct disk identifier (in this case it was /dev/disk1); in diskutil list you'...
lid's user avatar
  • 1,855
2 votes

My Fusion Drive Partitioning Seems Wrong/Strange/Wonky

This procedure is going to get you back to a "factory fresh" system where your 128GB SSD and 3TB (spinning) HDD are configured as a Fusion Drive. Basically, we're going to: Delete all ...
Allan's user avatar
  • 103k
2 votes

Need Help Fixing Partitioning after Deleting Core Storage Booter and Windows

You deleted too many partitions. You deleted the booter partition used to boot Yosemite. Normally, the command given below would be used to reclaim the missing space. diskutil cs resizestack ...
David Anderson's user avatar
2 votes

Mac mini FusionDrive - “No CoreStorage Logical Volume Groups Found”

Once you're converted to APFS, CoreStorage is managed differently. Your result for diskutil list correctly shows both internal physical drives & the synthesised drive the OS constructs from that. ...
Tetsujin's user avatar
  • 117k
2 votes

Shrinking a Core Storage volume without the booter partition

I followed David Anderson's advice and discovered that the partition (as described by GPT) is 3584 bytes (7 LBA blocks) larger than the Core Storage Physical Volume. Using this information, I did ...
tonywu7's user avatar
  • 51
1 vote
Accepted

How do I consolidate all my partitions into one partition usable for Bootcamp?

Boot to Internet Recovery Mode and open Disk Utility. Repartition each disk to one partition, GUID partition table and OS X Extended (Journaled). Exit Disk Utility, open Terminal in the menubar > ...
klanomath's user avatar
  • 66.6k
1 vote
Accepted

How do I merge the 8 GB of "free space" on Macintosh HD under Logical volume group into Macintosh HD?

Resizing a Logical Volume in a larger Logical Volume Group with some free space is done with the undocumented coreStorage-verb resizeVolume: diskutil cs resizeVolume lvUUID size with lvUUID: UUID of ...
klanomath's user avatar
  • 66.6k
1 vote
Accepted

Many 0.1 -6 mb + disk images on running "diskutil list"under "Recovery HD". Is it normal?

Yes - the recovery HD layers many components to make a bootable system so I would call that normal / intended. Since you are booting to a write restricted environment on an OS that typically wants to ...
bmike's user avatar
  • 238k
1 vote

Where are Core Storage instructions stored?

Without a recovery partition you can't enable FileVault 2: https://support.apple.com/en-us/HT204837 "Without a Recovery System, FileVault won't encrypt your startup drive." I'll bet CoreStorage ...
MacManager's user avatar
  • 1,714

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