I am using a 2011 MacBook Pro 15", this is the model with the AMD GPU problems and I have used the NVRAM modification to disable the AMD GPU and then Dosdude's patch to install Catalina.
This is a usable laptop with an i7 and 16GB of RAM so it runs Catalina fine. A month or so ago, I partitioned the drive and Installed Ubuntu 20.04, changing the Grub configuration to disable the faulty GPU and force it to use the integrated Intel GPU. I use Refind as a boot manager and all was well until I tried to boot Mac OS today.
A couple of days ago, I wanted to make more space for Ubuntu as I found I was using it a lot. I repartitioned the Mac APFS partition to give another 50GB of space that I planned to add to the Ubuntu partition. I then continued to use Mac OS for 2 days, sleeping instead of shutting it down. Last night I shut it down and this morning the Mac partition does not appear in Refind or in the ALT boot menu. Ubuntu still boots and I can still "see" the Mac partition from Gparted. It looks like the GPT is corrupt but I am not sure how to use Gdisk to fix it from Ubuntu.
This is my lsblk readout from Ubuntu...
$ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT loop0 7:0 0 49.8M 1 loop /snap/snap-store/433 loop1 7:1 0 144.4M 1 loop /snap/code/38 loop2 7:2 0 240.8M 1 loop /snap/gnome-3-34-1804/24 loop3 7:3 0 55M 1 loop /snap/core18/1754 loop4 7:4 0 97M 1 loop /snap/core/9665 loop5 7:5 0 29.9M 1 loop /snap/snapd/8542 loop6 7:6 0 255.6M 1 loop /snap/gnome-3-34-1804/36 loop7 7:7 0 800.4M 1 loop /snap/android-studio/90 loop8 7:8 0 9.1M 1 loop /snap/canonical-livepatch/95 loop9 7:9 0 55M 1 loop /snap/core18/1880 loop10 7:10 0 29.8M 1 loop /snap/snapd/8140 loop11 7:11 0 49.8M 1 loop /snap/snap-store/467 loop12 7:12 0 800.4M 1 loop /snap/android-studio/91 loop13 7:13 0 141.6M 1 loop /snap/code/39 loop14 7:14 0 96.5M 1 loop /snap/core/9436 loop15 7:15 0 62.1M 1 loop /snap/gtk-common-themes/1506 sda 8:0 0 698.7G 0 disk ├─sda1 8:1 0 200M 0 part /boot/efi ├─sda2 8:2 0 465.7G 0 part └─sda4 8:4 0 187.3G 0 part / sr0 11:0 1 1024M 0 rom
The Mac partition is sda2 and the Ubuntu partition is sda4, the new empty space I created would be sda3 but is currently empty space.
My Gdisk initial readout is:
sudo gdisk /dev/sda GPT fdisk (gdisk) version 1.0.5 Partition table scan: MBR: hybrid BSD: not present APM: not present GPT: present Found valid GPT with hybrid MBR; using GPT.
Can anyone guide me in what I need to do to get Mac OS booting again...
Here is the first piece of requested information:
$ sudo gdisk -l /dev/sda GPT fdisk (gdisk) version 1.0.5 Partition table scan: MBR: hybrid BSD: not present APM: not present GPT: present Found valid GPT with hybrid MBR; using GPT. Disk /dev/sda: 1465149168 sectors, 698.6 GiB Model: TOSHIBA MK7559GS Sector size (logical/physical): 512/4096 bytes Disk identifier (GUID): 6C152A2F-A973-45DC-8157-2C45FDEDF3E7 Partition table holds up to 128 entries Main partition table begins at sector 2 and ends at sector 33 First usable sector is 34, last usable sector is 1465149134 Partitions will be aligned on 8-sector boundaries Total free space is 95220781 sectors (45.4 GiB) Number Start (sector) End (sector) Size Code Name 1 40 409639 200.0 MiB EF00 EFI System Partition 2 409640 977103527 465.7 GiB FFFF 4 1072322560 1465147391 187.3 GiB 8300
and here is the second bit:
sudo fdisk -l /dev/sda Disk /dev/sda: 698.65 GiB, 750156374016 bytes, 1465149168 sectors Disk model: TOSHIBA MK7559GS Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: gpt Disk identifier: 6C152A2F-A973-45DC-8157-2C45FDEDF3E7 Device Start End Sectors Size Type /dev/sda1 40 409639 409600 200M EFI System /dev/sda2 409640 977103527 976693888 465.7G unknown /dev/sda4 1072322560 1465147391 392824832 187.3G Linux filesystem
I can't currently get into recovery mode as there is no recovery partition and the wifi is via a usb dongle.