Can't boot into kubuntu after replacing Manjaro on second drive [Dual-Boot Setup with Windows on first drive]

Question

I have trouble fixing my dual boot setup (Windows on the first, Kubuntu on the second drive). I had previously installed Manjaro on the second drive and the installation of Kubuntu (overwriting Manjaro) probably messed up the booting process. Now Kubuntu is installed, but unfortunately I can't boot into Kubuntu. Using the boot-repair (https://help.ubuntu.com/community/Boot-Repair) tool didn't fix this issue.

Any help would be greatly appreciated.

Thanks

Diagnostics from https://paste.ubuntu.com/p/D9vTmrsq2d/:

boot-repair-4ppa200                                              [20220329_2030]
============================= Boot Repair Summary ==============================
=================== /boot detected. Please check the options.
Recommended repair: ____________________________________________________________
The default repair of the Boot-Repair utility will reinstall the grub-efi of
nvme0n1p4,
using the following options:  nvme0n1p2/boot sda2/boot/efi
Additional repair will be performed: unhide-bootmenu-10s use-standard-efi-file
Mount nvme0n1p2 on /mnt/boot-sav/nvme0n1p4/boot
Mount sda2 on /mnt/boot-sav/nvme0n1p4/boot/efi
Unhide GRUB boot menu in nvme0n1p4/etc/default/grub
===================== Reinstall the grub-efi of nvme0n1p4 ======================
chroot /mnt/boot-sav/nvme0n1p4 grub-install --version
grub-install (GRUB) 2.04-1ubuntu26.13
chroot /mnt/boot-sav/nvme0n1p4 modprobe efivars
chroot /mnt/boot-sav/nvme0n1p4 efibootmgr -v before grub install
BootCurrent: 001D
Timeout: 0 seconds
BootOrder: 001B,001C,0000,0001,001D,0018,0019,001A,001E
Boot0000* Windows Boot Manager  HD(2,GPT,2a708f04-f63c-4315-aba9-2a927622cc2a,0x109000,0x31800)/File(efimanjarogrubx64.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...h................
Boot0001* Manjaro   HD(1,GPT,87383e60-9017-8147-9e12-b09549a2ea47,0x22,0x1007de)/File(EFIManjarogrubx64.efi)
Boot0010  Setup FvFile(721c8b66-426c-4e86-8e99-3457c46ab0b9)
Boot0011  Boot Menu FvFile(126a762d-5758-4fca-8531-201a7f57f850)
Boot0012  Diagnostic Splash Screen  FvFile(a7d8d9a6-6ab0-4aeb-ad9d-163e59a7a380)
Boot0013  Lenovo Diagnostics    FvFile(3f7e615b-0d45-4f80-88dc-26b234958560)
Boot0014  Regulatory Information    FvFile(478c92a0-2622-42b7-a65d-5894169e4d24)
Boot0015  Startup Interrupt Menu    FvFile(f46ee6f4-4785-43a3-923d-7f786c3c8479)
Boot0016  Rescue and Recovery   FvFile(665d3f60-ad3e-4cad-8e26-db46eee9f1b5)
Boot0017  MEBx Hot Key  FvFile(ac6fd56a-3d41-4efd-a1b9-870293811a28)
Boot0018* USB CD    VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,86701296aa5a7848b66cd49dd3ba6a55)
Boot0019* USB FDD   VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,6ff015a28830b543a8b8641009461e49)
Boot001A* NVMe0 VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,001c199932d94c4eae9aa0b6e98eb8a400)
Boot001B* ATA HDD0  VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,91af625956449f41a7b91f4f892ab0f600)
Boot001C* ATA HDD1  VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,91af625956449f41a7b91f4f892ab0f601)
Boot001D* USB HDD   VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,33e821aaaf33bc4789bd419f88c50803)
Boot001E* PCI LAN   VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,78a84aaf2b2afc4ea79cf5cc8f3d3803)
Boot001F* IDER BOOT CDROM   PciRoot(0x0)/Pci(0x14,0x0)/USB(11,1)
Boot0020* IDER BOOT Floppy  PciRoot(0x0)/Pci(0x14,0x0)/USB(11,0)
Boot0021* ATA HDD   VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,91af625956449f41a7b91f4f892ab0f6)
Boot0022* ATAPI CD  VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,aea2090adfde214e8b3a5e471856a354)
chroot /mnt/boot-sav/nvme0n1p4 uname -r
5.13.0-30-generic
chroot /mnt/boot-sav/nvme0n1p4 grub-install --efi-directory=/boot/efi --target=x86_64-efi
Installing for x86_64-efi platform.
Installation finished. No error reported.
df /dev/sda2
mv /mnt/boot-sav/nvme0n1p4/boot/efi/EFI/Boot/bootx64.efi /mnt/boot-sav/nvme0n1p4/boot/efi/EFI/Boot/bkpbootx64.efi
cp /mnt/boot-sav/nvme0n1p4/boot/efi/efi/ubuntu/grubx64.efi /mnt/boot-sav/nvme0n1p4/boot/efi/EFI/Boot/bootx64.efi
chroot /mnt/boot-sav/nvme0n1p4 grub-install --efi-directory=/boot/efi --target=x86_64-efi
Installing for x86_64-efi platform.
Installation finished. No error reported.
chroot /mnt/boot-sav/nvme0n1p4 efibootmgr -v after grub install
BootCurrent: 001D
Timeout: 0 seconds
BootOrder: 0002,001B,001C,0000,0001,001D,0018,0019,001A,001E
Boot0000* Windows Boot Manager  HD(2,GPT,2a708f04-f63c-4315-aba9-2a927622cc2a,0x109000,0x31800)/File(efimanjarogrubx64.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...h................
Boot0001* Manjaro   HD(1,GPT,87383e60-9017-8147-9e12-b09549a2ea47,0x22,0x1007de)/File(EFIManjarogrubx64.efi)
Boot0002* ubuntu    HD(2,GPT,2a708f04-f63c-4315-aba9-2a927622cc2a,0x109000,0x31800)/File(EFIubuntushimx64.efi)
Boot0010  Setup FvFile(721c8b66-426c-4e86-8e99-3457c46ab0b9)
Boot0011  Boot Menu FvFile(126a762d-5758-4fca-8531-201a7f57f850)
Boot0012  Diagnostic Splash Screen  FvFile(a7d8d9a6-6ab0-4aeb-ad9d-163e59a7a380)
Boot0013  Lenovo Diagnostics    FvFile(3f7e615b-0d45-4f80-88dc-26b234958560)
Boot0014  Regulatory Information    FvFile(478c92a0-2622-42b7-a65d-5894169e4d24)
Boot0015  Startup Interrupt Menu    FvFile(f46ee6f4-4785-43a3-923d-7f786c3c8479)
Boot0016  Rescue and Recovery   FvFile(665d3f60-ad3e-4cad-8e26-db46eee9f1b5)
Boot0017  MEBx Hot Key  FvFile(ac6fd56a-3d41-4efd-a1b9-870293811a28)
Boot0018* USB CD    VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,86701296aa5a7848b66cd49dd3ba6a55)
Boot0019* USB FDD   VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,6ff015a28830b543a8b8641009461e49)
Boot001A* NVMe0 VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,001c199932d94c4eae9aa0b6e98eb8a400)
Boot001B* ATA HDD0  VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,91af625956449f41a7b91f4f892ab0f600)
Boot001C* ATA HDD1  VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,91af625956449f41a7b91f4f892ab0f601)
Boot001D* USB HDD   VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,33e821aaaf33bc4789bd419f88c50803)
Boot001E* PCI LAN   VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,78a84aaf2b2afc4ea79cf5cc8f3d3803)
Boot001F* IDER BOOT CDROM   PciRoot(0x0)/Pci(0x14,0x0)/USB(11,1)
Boot0020* IDER BOOT Floppy  PciRoot(0x0)/Pci(0x14,0x0)/USB(11,0)
Boot0021* ATA HDD   VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,91af625956449f41a7b91f4f892ab0f6)
Boot0022* ATAPI CD  VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,aea2090adfde214e8b3a5e471856a354)
chroot /mnt/boot-sav/nvme0n1p4 update-grub
Sourcing file /etc/default/grub' Sourcing file/etc/default/grub.d/init-select.cfg'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-5.13.0-39-generic
Found initrd image: /boot/initrd.img-5.13.0-39-generic
Found linux image: /boot/vmlinuz-5.13.0-30-generic
Found initrd image: /boot/initrd.img-5.13.0-30-generic
Found Windows Boot Manager on /dev/sda2@/EFI/Microsoft/Boot/bootmgfw.efi
Adding boot menu entry for UEFI Firmware Settings
Boot successfully repaired.
You can now reboot your computer.
Please do not forget to make your UEFI firmware boot on the Ubuntu 20.04.4 LTS entry (sda2/efi/ubuntu/grubx64.efi file) !
If your computer reboots directly into Windows, try to change the boot order in your UEFI firmware.
If your UEFI firmware does not allow to change the boot order, change the default boot entry of the Windows bootloader.
For example you can boot into Windows, then type the following command in an admin command prompt:
bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi
============================ Boot Info After Repair ============================
=> Windows 7/8/10/11/2012 is installed in the MBR of /dev/nvme0n1.
 => Windows 7/8/10/11/2012 is installed in the MBR of /dev/sda.
 => Syslinux MBR (5.00 and higher) is installed in the MBR of /dev/sdb.
nvme0n1p1: _____________________________________________________________________
File system:       
Boot sector type:  -
Boot sector info: 


nvme0n1p2: _____________________________________________________________________
File system:       ext4
Boot sector type:  -
Boot sector info: 
Operating System:  
Boot files:        /grub/grub.cfg


nvme0n1p3: _____________________________________________________________________
File system:       swap
Boot sector type:  -
Boot sector info: 


nvme0n1p4: _____________________________________________________________________
File system:       ext4
Boot sector type:  -
Boot sector info: 
Operating System:  Ubuntu 20.04.4 LTS
Boot files:        /etc/fstab /etc/default/grub


sda1: __________________________________________________________________________
File system:       ntfs
Boot sector type:  Windows 8/10/11/2012: NTFS
Boot sector info:  No errors found in the Boot Parameter Block.
Operating System:  
Boot files:        


sda2: __________________________________________________________________________
File system:       vfat
Boot sector type:  Windows 8/10/11/2012: FAT32
Boot sector info:  No errors found in the Boot Parameter Block.
Operating System:  
Boot files:        /efi/Boot/bkpbootx64.efi /efi/Boot/bootx64.efi 
                   /efi/Boot/fbx64.efi /efi/Boot/mmx64.efi 
                   /efi/ubuntu/grubx64.efi /efi/ubuntu/mmx64.efi 
                   /efi/ubuntu/shimx64.efi /efi/ubuntu/grub.cfg 
                   /efi/Microsoft/Boot/bootmgfw.efi 
                   /efi/Microsoft/Boot/bootmgr.efi


sda3: __________________________________________________________________________
File system:       
Boot sector type:  -
Boot sector info: 


sda4: __________________________________________________________________________
File system:       ntfs
Boot sector type:  Windows 8/10/11/2012: NTFS
Boot sector info:  No errors found in the Boot Parameter Block.
Operating System:  Windows 8 or 10
Boot files:        /Windows/System32/winload.exe


sda5: __________________________________________________________________________
File system:       ntfs
Boot sector type:  Windows 8/10/11/2012: NTFS
Boot sector info:  No errors found in the Boot Parameter Block.
Operating System:  
Boot files:        


sdb1: __________________________________________________________________________
File system:       vfat
Boot sector type:  SYSLINUX 6.04
Boot sector info:  Syslinux looks at sector 32816 of /dev/sdb1 for its 
                   second stage. The integrity check of Syslinux failed. 
                   No errors found in the Boot Parameter Block.
Operating System:  
Boot files:        /boot/grub/grub.cfg /syslinux.cfg 
                   /efi/BOOT/grubx64.efi /efi/BOOT/mmx64.efi /ldlinux.sys



================================ 2 OS detected =================================
OS#1:   Ubuntu 20.04.4 LTS on nvme0n1p4
OS#2:   Windows 8 or 10 on sda4
================================ Host/Hardware =================================
CPU architecture: 64-bit
Video: UHD Graphics 620 (Whiskey Lake) from Intel Corporation
Live-session OS is Ubuntu 64-bit (Ubuntu 20.04.4 LTS, focal, x86_64)
===================================== UEFI =====================================
BIOS/UEFI firmware: R0YET42W (1.25 )(1.25) from LENOVO
The firmware is EFI-compatible, and is set in EFI-mode for this live-session.
SecureBoot disabled - SecureBoot disabled - Please report this message to boot.repair@gmail.com.
BootCurrent: 001D
Timeout: 0 seconds
BootOrder: 0002,001B,001C,0000,0001,001D,0018,0019,001A,001E
Boot0000* Windows Boot Manager  HD(2,GPT,2a708f04-f63c-4315-aba9-2a927622cc2a,0x109000,0x31800)/File(\efi\manjaro\grubx64.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...h................
Boot0001* Manjaro   HD(1,GPT,87383e60-9017-8147-9e12-b09549a2ea47,0x22,0x1007de)/File(\EFI\Manjaro\grubx64.efi)
Boot0010  Setup FvFile(721c8b66-426c-4e86-8e99-3457c46ab0b9)
Boot0011  Boot Menu FvFile(126a762d-5758-4fca-8531-201a7f57f850)
Boot0012  Diagnostic Splash Screen  FvFile(a7d8d9a6-6ab0-4aeb-ad9d-163e59a7a380)
Boot0013  Lenovo Diagnostics    FvFile(3f7e615b-0d45-4f80-88dc-26b234958560)
Boot0014  Regulatory Information    FvFile(478c92a0-2622-42b7-a65d-5894169e4d24)
Boot0015  Startup Interrupt Menu    FvFile(f46ee6f4-4785-43a3-923d-7f786c3c8479)
Boot0016  Rescue and Recovery   FvFile(665d3f60-ad3e-4cad-8e26-db46eee9f1b5)
Boot0017  MEBx Hot Key  FvFile(ac6fd56a-3d41-4efd-a1b9-870293811a28)
Boot0018* USB CD    VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,86701296aa5a7848b66cd49dd3ba6a55)
Boot0019* USB FDD   VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,6ff015a28830b543a8b8641009461e49)
Boot001A* NVMe0 VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,001c199932d94c4eae9aa0b6e98eb8a400)
Boot001B* ATA HDD0  VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,91af625956449f41a7b91f4f892ab0f600)
Boot001C* ATA HDD1  VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,91af625956449f41a7b91f4f892ab0f601)
Boot001D* USB HDD   VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,33e821aaaf33bc4789bd419f88c50803)
Boot001E* PCI LAN   VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,78a84aaf2b2afc4ea79cf5cc8f3d3803)
Boot001F* IDER BOOT CDROM   PciRoot(0x0)/Pci(0x14,0x0)/USB(11,1)
Boot0020* IDER BOOT Floppy  PciRoot(0x0)/Pci(0x14,0x0)/USB(11,0)
Boot0021* ATA HDD   VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,91af625956449f41a7b91f4f892ab0f6)
Boot0022* ATAPI CD  VenMsg(bc7838d2-0f82-4d60-8316-c068ee79d25b,aea2090adfde214e8b3a5e471856a354)
728124f6ec8e22fbdbe7034812c81b95   sda2/Boot/bkpbootx64.efi
728124f6ec8e22fbdbe7034812c81b95   sda2/Boot/bootx64.efi
85fa9d77b929ec4231aba29476574eb6   sda2/Boot/fbx64.efi
469e608783843a701d172242f016c79c   sda2/Boot/mmx64.efi
fa1bf1a7f90a852abe0bdbd089b7f1b0   sda2/ubuntu/grubx64.efi
469e608783843a701d172242f016c79c   sda2/ubuntu/mmx64.efi
728124f6ec8e22fbdbe7034812c81b95   sda2/ubuntu/shimx64.efi
0e21ee9bfb9bbf0f31dfe80eb99a660f   sda2/Microsoft/Boot/bootmgfw.efi
350fb977baa35b0f02392077ab3d1f67   sda2/Microsoft/Boot/bootmgr.efi
============================= Drive/Partition Info =============================
Disks info: ____________________________________________________________________
nvme0n1 : is-GPT,   no-BIOSboot,    has-noESP,  not-usb,    not-mmc, has-os,    no-wind,    34 sectors * 512 bytes
sda : is-GPT,   no-BIOSboot,    has---ESP,  not-usb,    not-mmc, has-os,    has-win,    2048 sectors * 512 bytes
Partitions info (1/3): _________________________________________________________
nvme0n1p2   : no-os,    32, nopakmgr,   no-docgrub, nogrub, nogrubinstall,  grubenv-ok, noupdategrub,   not-far
nvme0n1p4   : is-os,    64, apt-get,    signed grub-pc grub-efi ,   grub2,  grub-install,   no-grubenv, update-grub,    farbios
sda1    : no-os,    32, nopakmgr,   no-docgrub, nogrub, nogrubinstall,  no-grubenv, noupdategrub,   not-far
sda2    : no-os,    32, nopakmgr,   no-docgrub, nogrub, nogrubinstall,  no-grubenv, noupdategrub,   not-far
sda4    : is-os,    32, nopakmgr,   no-docgrub, nogrub, nogrubinstall,  no-grubenv, noupdategrub,   farbios
sda5    : no-os,    32, nopakmgr,   no-docgrub, nogrub, nogrubinstall,  no-grubenv, noupdategrub,   farbios
Partitions info (2/3): _________________________________________________________
nvme0n1p2   : isnotESP, part-has-no-fstab,  no-nt,  no-winload, no-recov-nor-hid,   no-bmgr,    notwinboot
nvme0n1p4   : isnotESP, fstab-has-goodEFI,  no-nt,  no-winload, no-recov-nor-hid,   no-bmgr,    notwinboot
sda1    : isnotESP, part-has-no-fstab,  no-nt,  no-winload, recovery-or-hidden, no-bmgr,    notwinboot
sda2    : is---ESP, part-has-no-fstab,  no-nt,  no-winload, no-recov-nor-hid,   no-bmgr,    notwinboot
sda4    : isnotESP, part-has-no-fstab,  no-nt,  haswinload, no-recov-nor-hid,   no-bmgr,    notwinboot
sda5    : isnotESP, part-has-no-fstab,  no-nt,  no-winload, recovery-or-hidden, no-bmgr,    notwinboot
Partitions info (3/3): _________________________________________________________
nvme0n1p2   : is---sepboot, no---boot,  part-has-no-fstab,  not-sep-usr,    no---usr,   part-has-no-fstab,  no--grub.d, nvme0n1
nvme0n1p4   : not--sepboot, no---boot,  fstab-has-goodBOOT, not-sep-usr,    with--usr,  fstab-without-usr,  std-grub.d, nvme0n1
sda1    : not--sepboot, no---boot,  part-has-no-fstab,  not-sep-usr,    no---usr,   part-has-no-fstab,  no--grub.d, sda
sda2    : not--sepboot, no---boot,  part-has-no-fstab,  not-sep-usr,    no---usr,   part-has-no-fstab,  no--grub.d, sda
sda4    : not--sepboot, no---boot,  part-has-no-fstab,  not-sep-usr,    no---usr,   part-has-no-fstab,  no--grub.d, sda
sda5    : not--sepboot, no---boot,  part-has-no-fstab,  not-sep-usr,    no---usr,   part-has-no-fstab,  no--grub.d, sda
fdisk -l (filtered): ___________________________________________________________
Disk nvme0n1: 238.49 GiB, 256060514304 bytes, 500118192 sectors
Disk identifier: 51CAB6B0-2B72-42E7-961D-0828F65FFEC6
             Start       End   Sectors   Size Type
nvme0n1p1       34     32767     32734    16M Microsoft reserved
nvme0n1p2    32768   1032191    999424   488M Linux filesystem
nvme0n1p3  1032192  32282623  31250432  14.9G Linux swap
nvme0n1p4 32282624 500117503 467834880 223.1G Linux filesystem
Disk sda: 465.78 GiB, 500107862016 bytes, 976773168 sectors
Disk identifier: 98C040ED-E666-4FD5-B0AA-49C2FBC529B5
          Start       End   Sectors   Size Type
sda1       2048   1085439   1083392   529M Windows recovery environment
sda2    1085440   1288191    202752    99M EFI System
sda3    1288192   1320959     32768    16M Microsoft reserved
sda4    1320960 975367367 974046408 464.5G Microsoft basic data
sda5  975368192 976771071   1402880   685M Windows recovery environment
Disk sdb: 14.93 GiB, 16008609792 bytes, 31266816 sectors
Disk identifier: 0x000e4fb2
      Boot Start      End  Sectors  Size Id Type
sdb1  *     2048 31266815 31264768 14.9G  c W95 FAT32 (LBA)
parted -lm (filtered): _________________________________________________________
sda:500GB:scsi:512:512:gpt:ATA CT500MX500SSD1:;
1:1049kB:556MB:555MB:ntfs:Basic data partition:hidden, diag;
2:556MB:660MB:104MB:fat32:EFI system partition:boot, esp;
3:660MB:676MB:16.8MB::Microsoft reserved partition:msftres;
4:676MB:499GB:499GB:ntfs:Basic data partition:msftdata;
5:499GB:500GB:718MB:ntfs::hidden, diag;
sdb:16.0GB:scsi:512:512:msdos:SanDisk Cruzer:;
1:1049kB:16.0GB:16.0GB:fat32::boot, lba;
nvme0n1:256GB:nvme:512:512:gpt:HFM256GDHTNG-8510B:;
1:17.4kB:16.8MB:16.8MB::Microsoft reserved partition:msftres;
2:16.8MB:528MB:512MB:ext4::;
3:528MB:16.5GB:16.0GB:linux-swap(v1)::swap;
4:16.5GB:256GB:240GB:ext4::;
blkid (filtered): ______________________________________________________________
NAME        FSTYPE   UUID                                 PARTUUID                             LABEL             PARTLABEL
sda

├─sda1      ntfs     8A0880C90880B5AB                     65fc2302-9544-46fe-bcf4-340206a60fc4 Wiederherstellung Basic data partition
├─sda2      vfat     8A81-77C1                            2a708f04-f63c-4315-aba9-2a927622cc2a                   EFI system partition
├─sda3                                                    5b637462-b63f-449d-b6e4-4947abb30242                   Microsoft reserved partition
├─sda4      ntfs     B8128780128741FC                     28d27607-0b4d-46db-98d1-95ae4de46241                   Basic data partition
└─sda5      ntfs     2CC6FA45C6FA0EB8                     7dccf049-1715-463b-80ac-e2a091c78c9d

sdb

└─sdb1      vfat     5633-3D0F                            000e4fb2-01                          KUBUNTU 20_

nvme0n1

├─nvme0n1p1                                               3b95a911-fc0d-401e-a69c-a487040ccfda                   Microsoft reserved partition
├─nvme0n1p2 ext4     2d5fabbe-e3ed-40f3-9302-a5380377fd11 48233f3b-a9ff-4a23-a1db-2fc504f56cd1

├─nvme0n1p3 swap     d449d374-919b-4858-b887-53b9f4b55b8c 3090d594-20b7-491f-afd5-343599b88ca6

└─nvme0n1p4 ext4     c936c5c2-9afe-4c9f-93e7-bf94f0220ca5 784226ac-524a-4824-a1e6-9cb8e2afbae0
Mount points (filtered): _______________________________________________________
            Avail Use% Mounted on

/dev/nvme0n1p2 194.1M  50% /mnt/boot-sav/nvme0n1p2
/dev/nvme0n1p4 201.1G   3% /mnt/boot-sav/nvme0n1p4
/dev/sda1        519M   2% /mnt/boot-sav/sda1
/dev/sda2       63.9M  33% /mnt/boot-sav/sda2
/dev/sda4       96.3G  79% /mnt/boot-sav/sda4
/dev/sda5       88.4M  87% /mnt/boot-sav/sda5
/dev/sdb1       11.7G  22% /cdrom
Mount options (filtered): ______________________________________________________
/dev/nvme0n1p2 ext4        rw,relatime
/dev/nvme0n1p4 ext4        rw,relatime
/dev/sda1      fuseblk     rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
/dev/sda2      vfat        rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro
/dev/sda4      fuseblk     rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
/dev/sda5      fuseblk     rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
/dev/sdb1      vfat        ro,noatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro
====================== nvme0n1p2/grub/grub.cfg (filtered) ======================
Ubuntu   c936c5c2-9afe-4c9f-93e7-bf94f0220ca5
Ubuntu, with Linux 5.13.0-39-generic   c936c5c2-9afe-4c9f-93e7-bf94f0220ca5
Ubuntu, with Linux 5.13.0-30-generic   c936c5c2-9afe-4c9f-93e7-bf94f0220ca5
Windows Boot Manager (on sda2)   osprober-efi-8A81-77C1
END /etc/grub.d/30_os-prober
UEFI Firmware Settings   uefi-firmware
END /etc/grub.d/30_uefi-firmware
================= nvme0n1p2: Location of files loaded by Grub ==================
       GiB - GB             File                                 Fragment(s)

0.375476837 = 0.403165184    grub/grub.cfg                                  3
   0.173534393 = 0.186331136    vmlinuz                                        1
   0.164058685 = 0.176156672    vmlinuz-5.13.0-30-generic                      2
   0.173534393 = 0.186331136    vmlinuz-5.13.0-39-generic                      1
   0.164058685 = 0.176156672    vmlinuz.old                                    2
   0.367183685 = 0.394260480    initrd.img                                     4
   0.482364655 = 0.517935104    initrd.img-5.13.0-30-generic                   2
   0.367183685 = 0.394260480    initrd.img-5.13.0-39-generic                   4
   0.482364655 = 0.517935104    initrd.img.old                                 2
======================== nvme0n1p4/etc/fstab (filtered) ========================
<file system> <mount point>   <type>  <options>       <dump>  <pass>
/ was on /dev/nvme0n1p4 during installation
UUID=c936c5c2-9afe-4c9f-93e7-bf94f0220ca5 /               ext4    errors=remount-ro 0       1
/boot was on /dev/nvme0n1p2 during installation
UUID=2d5fabbe-e3ed-40f3-9302-a5380377fd11 /boot           ext4    defaults        0       2
/boot/efi was on /dev/sda2 during installation
UUID=8A81-77C1  /boot/efi       vfat    umask=0077      0       1
swap was on /dev/nvme0n1p3 during installation
UUID=d449d374-919b-4858-b887-53b9f4b55b8c none            swap    sw              0       0
==================== nvme0n1p4/etc/default/grub (filtered) =====================
GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=menu
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=lsb_release -i -s 2&gt; /dev/null || echo Debian
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""
GRUB_DISABLE_OS_PROBER=false
=================== nvme0n1p4: ls -l /etc/grub.d/ (filtered) ===================
-rwxr-xr-x 1 root root 18151 Aug 12  2021 10_linux
-rwxr-xr-x 1 root root 42359 Aug 12  2021 10_linux_zfs
-rwxr-xr-x 1 root root 12894 Aug 12  2021 20_linux_xen
-rwxr-xr-x 1 root root 12059 Aug 12  2021 30_os-prober
-rwxr-xr-x 1 root root  1424 Aug 12  2021 30_uefi-firmware
-rwxr-xr-x 1 root root   214 Aug 12  2021 40_custom
-rwxr-xr-x 1 root root   216 Aug 12  2021 41_custom
===================== sda2/efi/ubuntu/grub.cfg (filtered) ======================
search.fs_uuid 2d5fabbe-e3ed-40f3-9302-a5380377fd11 root 
set prefix=($root)'/grub'
configfile $prefix/grub.cfg
====================== sdb1/boot/grub/grub.cfg (filtered) ======================
Start Kubuntu
Start Kubuntu (safe graphics)
OEM install (for manufacturers)
Boot from next volume
UEFI Firmware Settings
========================= sdb1/syslinux.cfg (filtered) =========================
DEFAULT loadconfig
LABEL loadconfig
  CONFIG /isolinux/isolinux.cfg
  APPEND /isolinux/
==================== sdb1: Location of files loaded by Grub ====================
       GiB - GB             File                                 Fragment(s)
        ?? = ??             boot/grub/grub.cfg                             1


================== sdb1: Location of files loaded by Syslinux ==================
       GiB - GB             File                                 Fragment(s)
        ?? = ??             syslinux.cfg                                   1
        ?? = ??             ldlinux.sys                                    1