Can I resize the macOS High Sierra HDD partition without losing data or making dual boot unusable?

I posted that ^ after I logged in macOS HS and installed the latest HS update (10.13.6, I think). Then I restarted in Windows and I noticed the High Sierra update destroyed the DOX partition, where I was keeping documents. This is what Disk Management in Windows shows, after the HS update:

Luckily, before I did this update I made a backup of all the documents on that partition, so I can restore them.

But I guess this accident might simplify things, because the BOOT (on drive A:\) partition was already empty, so right now, on the physical (HDD) disk there is only one working partition, the macOS HS one. So, can I resize that partition and still have Bootcamp and dual boot still work?

Then I could re-partition that space and restore my documents on a new HDD partition.

Terminal diskutil:

➜  ~  diskutil list
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *240.1 GB   disk0
   1:               Windows_NTFS SSD                     239.2 GB   disk0s1
   2:                       0x27                         900.7 MB   disk0s2

/dev/disk1 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.1 GB   disk1
   1:                        EFI EFI                     209.7 MB   disk1s1
   2:                  Apple_HFS HDD                     307.4 GB   disk1s2
   3:                 Apple_Boot                         650.0 MB   disk1s3
   4:       Microsoft Basic Data BOOT                    41.7 GB    disk1s4
   5:       Microsoft Basic Data DOX                     150.0 GB   disk1s5

/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                                                   *320.1 GB   disk2

/dev/disk3 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.1 GB   disk3
   1:                        EFI EFI                     209.7 MB   disk3s1
   2:       Microsoft Basic Data                         306.2 GB   disk3s2
   3:       Microsoft Basic Data                         42.0 GB    disk3s3
   4:                  Apple_HFS                         134.2 MB   disk3s4
   5:       Microsoft Basic Data Copy of C               150.0 GB   disk2s5
   6:       Microsoft Basic Data New Volume              1.4 GB     disk2s6

   5:       Microsoft Basic Data Copy of C               150.0 GB   disk3s5
   6:       Microsoft Basic Data New Volume              1.4 GB     disk3s6

disk0 is the internal SSD with Windows 10

disk1 is the internal HDD with the macOS partition and the other 2 data partitions (BOOT is empty and still visible in Windows, DOX still has documents in it but is no longer visible in Windows after the High Sierra update) - the others are not visible (EFI, Apple_boot)

disk2 is an external hard-disk (320GB), basically it's a former internal disk from a Powerbook that was repurposed as an external backup drive -- currently cannot be mounted on any system, I even tried to format it in Windows and it failed (possible physical issues)

disk3 is an external hard-disk (LaCie Quadra 500GB) which had 4 partitions, of which only 2 are visible right now (Copy of C and New Volume - not sure how they got these names). These 2 are visible in Windows too, the others are invisible.

Now I will post how Disk Utilities sees and identifies these disks:

disk0 - skipping this one, it has no issues

disk1 -

disk2 - the one I think it might be physically kaput

disk3 - the LaCie external disk - (ignore the disk2 identifier, it got re-assigned as disk2 after I unplugged the previous external drive)

These are its children (starting from 2, because 1 is EFI):

I don't remember setting these names, it's possible they were created automatically when I once cloned a partition from Windows which was assigned to C. The "New Volume" one may have also been created with a default name. I'm not sure why this partition is so small, though, maybe it cloned some leftover space from the disk. Some Mac OS X Lion partition has also been cloned on this external drive. They were both bootable, I think, which is maybe why there are EFI and Apple_HFS hidden chunks in there. However, this never caused any issue and this drive has very rarely been used. It hasn't been used for months until yesterday and last time I connected it to the macmini it was working right, all partitions showed up both in Windows and macOS.

So, to see both external drives have failures all of a sudden is weird. They weren't dropped or exposed to any shocks, as far as I know, they were kept in a drawer.

Anyway, it would be great if I could at least recover the data on the LaCie drive, so I can transfer it to another external drive (I have another LaCie drive of 2TB I recently bought, but 30% of its space is used, so I couldn't use it for Time Machine, it only has one partition) and then use the disk for Time Machine.

Thanks for your time, I appreciate any help or idea you might have.

Recovery mode finished loading after about 40 minutes.

I picked Disk Utilities from the menu, but both the SSD drive (the one with Windows 10) and the HDD (the one with macOs) are shown in red. When I click any of them, it asks me whether I want to fix their errors by erasing them. I understand why that might be the case with the hdd macos drive, but what does Recovery have to do with the Windows drive from another physical drive?

Does this mean there's something wrong with Bootcamp which affects both physical drives?

Sorry about the quality of the pics, I'm posting from an old tablet.

How can this be fixed?

Computer                                                                       
Computer Brand Name:                                                            Apple Macmini6,1


Motherboard                                                                    
Motherboard Model:                                                              Apple Mac-031AEE4D24BFF0B1
Motherboard Chipset:                                                            Intel HM77 (Panther Point)
Motherboard Slots:                                                              4xPCI, 3xPCI Express x1, 1xPCI Express x16
PCI Express Version Supported:                                                  v3.0
USB Version Supported:                                                          v3.0


PCH Features                                                                   
USB Port Count:                                                                 14 ports
RAID Capability:                                                                RAID0/1/5/10 + Smart Response Technology
SATA Ports 2 and 3:                                                             Supported
SATA Port 1 6 Gb/s:                                                             Supported
SATA Port 0 6 Gb/s:                                                             Supported
PCI Interface:                                                                  Not Supported
PCI Express Ports 5 and 6:                                                      Supported
USB Redirect (USBr):                                                            Not Supported
Intel Anti-Theft Technology:                                                    Not Supported
PCI Express Ports 7 and 8:                                                      Supported
PCH Integrated Graphics Support:                                                Supported
Data Center Manageability Interface (DCMI):                                     Supported
Node Manager:                                                                   Supported


BIOS                                                                           
BIOS Manufacturer:                                                              Insyde Software
BIOS Date:                                                                      08/08/2017
BIOS Version:                                                                   MM61.88Z.010B.B00.1708080649
UEFI BIOS:                                                                      Capable


Super-IO/LPC Chip:                                                              Unknown

This is a late 2012 macmini (6,1), which is reported to be UEFI-compliant.

Initially, there was only one internal drive, the 500GB HDD that shipped with the unit. The original OS was probably Mavericks. It was subsequently upgraded to Yosemite, El Capitain etc until High Sierra. At some point I used Bootcamp to install Windows 8.1. I don't remember exactly which OS X version was used to create the original Bootcamp partition, might have been Mavericks.

The Windows 8.1 was eventually upgraded to Windows 10. I think that might explain why the original Bootcamp partition can still be found on the internal HDD, but now it's just an empty data partition (called DOX), it has no OS on it. This older Bootcamp partition can only be seen now on macOS, after the High Sierra update 10.13.6. Just a week ago, it was still usable in Windows 10, I was keeping documents on it. But after the HS update, it's gone, only accessible in macOS.

Here, I made a diagram which shows the current layout for both internal disks, based on what is visible from the Disk Management tool (Win10):

The SSD Windows installation was made with this macmini 6,1. The internal disk wasn't transferred from anywhere, it was a new device that was directly installed in the macmini.

However, when I installed Windows 10 as an upgrade from 8.1, the installer asked me to reformat the SSD unit as NTFS, which is the standard procedure for Windows installers now. Maybe the Win installer also made changes to the partition scheme, I've no idea, I didn't check whether there was a change back then.

Bootcamp used to update itself without any issues. Also disk drives formatted by macOS were readable on the Windows side and I could copy files from them. At some point, they disappeared, I'm not sure what caused the change.

So I tried to find a solution to make them visible again. I may have installed some third-party NTFS driver to make the drives on the internal hard disk (that were once formatted by macOS or OS X) visible again on the Windows side. Later on, I realised this NTFS driver had some side effects and decided to disable it, using a tool downloaded from Microsoft's official site for various developer tools.

Everything was still working right, there were no issues with booting in either system and I could still use the DOX and BOOT drives from the internal hard-disk drive. This changed after the macOS High Sierra update which made the DOX partition I was using for documents invisible on Windows. It can be accessed normally in macOS, even though when I listed partitions using `diskutil list`, DOX was classified as a Microsoft Data partition. And yet, it's not accessible on Windows.

I managed to fix the external LaCie drive, with your help, and created 2 partitions on it: one reserved for Time Machine (HFS+) and one for transferring documents between systems (FAT32). The external disk was formatted with a GPT scheme.

Then I made a full TM backup of the macOS HS system on this external LaCie drive. I booted in Recovery mode, which took a very long time to load, almost an hour, and I tried to fix the internal HDD partition issues with Disk Utilities. I wanted to erase the internal HDD, reformat it and partition it with 2 partitions: 1 for macOS and another one for documents (FAT32). The Recovery mode Disk Utilities displayed all internal disks (including the SSD) in red. When I tried to select the internal HDD only, it told me it had errors and I could only fix them by erasing all internal disks (including the SSD). I could not use this option, so I left Recovery without making any change.

Then I tried to reboot in macOS. This took almost one hour, even though usually, even on this older HDD, it only takes a few seconds to boot in macOS. Maybe the system was cleaning up or making changes after the Recovery session. First time it failed, the loader got stuck, so I had to power-reset it. It was booting again in macOS and was still very slow to load. So I rebooted again and tried to reach Recovery with Cmd+R in order to use the Terminal and bless the Windows partition, so I could reboot there. I couldn't access Recovery again, it just ignored my input.

Eventually, it managed to get in macOS again. I tried to use Disk Utilities to reformat DOX as FAT32. The operation was rejected with an error message: could not unmount the DOX volume.

Then I went back to Windows and used gdisk in the Command Prompt to see whether I get the same information as GPT fdisk in macOS Terminal. Information was slightly different, as you can see from what I posted above. Gdisk on the Windows side sees both an MBR and corrupted GPT partition scheme on the SSD drive, while GPT fdisk in Terminal under macOS sees the SSD partition as "FDisk partition scheme" (which I think it means MBR).

That's a short summary of what happened until now in this case.

There's no Microsoft directory visible in the mounted EFI partition. Only one Apple directory which has one empty directory and two with firmware files in them.

The boot options menu doesn't show up when pressing Alt/Opt immediately after the power-on beep. I tried it both while restarting from macOS to macOS and from macOS to Windows. No sign of a boot options menu. I haven't seen that menu for a long time, I think it used to appear once on the screen, but maybe some Bootcamp update or some system upgrade changed something.

Both Cmd-R and Cmd-Opt-R lead to Internet Recovery for me. After hitting either, there is a spinning globe animation on a black background and the words "Internet Recovery..." flash on the screen for a short while. Then it displays a loading timer 1.0...

Cmd-R leads into the old "OS X Utilities" version 1.0 (53)

Cmd-Opt-R leads in the newer "macOS Utilities" version 1.0 (327)

In the new Utilities mode:

- the Terminal does have access to csrutil and confirms that SIP is enabled.

- the DOX partition which I formatted as ReFS in Windows is greyed out and reports an MS-DOS FAT format

- start-up disks are displayed correctly as: HDD (macOS) and SDD (Windows)

In the old Utilities mode:

- csrutil is missing

- I think DOX is not displayed, only HDD and SSD

- the only start-up disk is SSD (Windows) now, but if you got in Recovery after choosing to restart in macOS from the Windows Bootcamp applet, you can just hit the Restart button and it will continue in macOS, even though this start-up option is missing

"disk 1" still shows up as a start-up disk in Windows Bootcamp:

Another change is that, after erasing the internal HDD drive and restoring macOS from the TM backup, gdisk32 reports the presence of a "protective MBR" for HDD (in Windows):

gdisk32 0: -l
GPT fdisk (gdisk) version 1.0.4


Partition table scan:
  MBR: protective

It used to be only "MBR present".

If I enable the start-up options menu for Win10, I get two options:

Same two options are displayed in System Properties too:

The first one is the current system. If I boot in the second option, it leads to an error screen which says this system has encountered an error and needs to be repaired, plus some other details.

So this seems to be a stub from a previous Win10 installation, which is still read as a valid boot option by Windows somehow. The weird part is that this wasn't there before I erased the HDD with the macOS partition. I think I still had two options in the Win10 boot menu, but not in the Bootcamp control panel.

Before the internal HDD was erased, I used to have 3 visible partitions on it: the macOS one, DOX (for documents) and BOOT, which used to have a bootable Win10 installation once too, that I eventually erased. So, when I came here on the forum to ask for advice, BOOT was already empty, but maybe it still had some intact boot entry somewhere, that somehow resurfaced after erasing the internal HDD. That wouldn't make sense, though, since I erased the whole disk using the macOS installer Disk Utilities.

It's a spare, empty partition that I once wanted to use for installing another instance of Windows 10 and keep it as an emergency solution, just in case something happened to the main Windows installation on the SSD drive. But I never used it, so it's an empty partition. It can be removed or merged into other partitions on the HDD without any issues.

I might be able to do that, though I'm not sure I understand how each step is done.

I have some external drives I might be able to use with Time Machine, but as far as I remember last time I used Time Machine, it tends to make the external disk unusable for anything else or with any other OS, right? I know it creates some limitations on how you can use the external disk, but not sure which. I think I wasn't able to partition the disk afterwards, or something like that. It tends to lock the disk in a certain state and then you cannot use the disk for anything else.

From which OS do I erase the 500GB disk? I suppose if I try to do this from the current macOS partition, it will refuse to do that, since Disk Utilities won't erase the OS on which it runs. So, I could only do that on the Windows side? Or from the macOS Recovery utility that I can access after the boot?

restore macOS on the full disk

How would I restore macOS if I erase the disk on which it was installed? From which OS can I do this operation?

Or is this possible by using the macOS Recovery utility that you can access by pressing Cmd R after rebooting and then using the "Restore from Time Machine backup" option?

At which point is the installer going to ask me to partition the erased 500GB disk?

Is changing things on the macOS side going to break the connection with the Bootcamp-installed Windows 10?

I'm just trying to make sure I understand the implications of each step, so I don't end up breaking other stuff in the process.

Thanks.

Well, this is like a chain of failures. Now I just discovered two of my external backup drives have failed. One failed completely and is unreadable by any computer (but it's fine, it was an older laptop disk repurposed as external drive), while the other (a LaCie quadra) failed partially (only 2 of 4 partitions are readable by any system).

The first external hdd might simply have a hardware failure, since it was kind of frail, but the LaCie is housed in a sturdy, thick metal case, it was not subjected to any shocks, and since two partitions still work, I assume there might be a logical failure (not necessarily physical).

Do you know if GPT fdisk is able to fix logical failures in external drives too? I've tried to read the drives with a hex editor and with a data recovery program, but both failed (first said it doesn't have permissions to read, the other said it doesn't recognise the file system).

I was planning on using one of these drives as a Time machine drive, but now I have to deal with a possibly bigger issue (loss of past data on the LaCie drive).

By the way, I logged in macOS High Sierra again and I can see the DOX partition again, but only in macOS (not in Windows). All the documents are on the partition too. So, apparently the logical structure of the disk is readable on the macOS side. This might be the result of the High Sierra update (10.13.6) which seems to have made some changes to that partition. Even though the file system is still labelled as Microsoft Basic Data (NTFS).

So maybe I don't even have to erase the whole internal physical disk (HDD) and restore from a TM backup. Maybe I can just reformat DOX from macOS HS and choose some FAT or NTFS-compatible format and then I might be able to see it again on the Windows side.

On another note, as I previously mentioned, ever since Bootcamp failed to update on the Windows side, the drive on which macOS is installed became unreadable in Windows. It used to be readable once.

There are some weird coincidences here and the Bootcamp driver failure to update might have played a role.

Anyway, if you have time to answer, can you make a suggestion on what I could use to read the LaCie external drive as a physical drive, to be able to recover the data, because I assume a partition table must still be on the drive, but somehow it's not recognised.

Secondly, should I just format the DOX partition on the macOS side in a format that is readable by Windows? It's already formatted as NTFS but somehow it's still not readable in Windows, but maybe if I formatted it as FAT32, it might become readable again. I've no idea which changes the High Sierra update might have made on how file systems are handled, so not sure if that's going to change much.