When I run fdisk, I get a warning message: > Partition table entries are not in disk order Here is an example of the command I'm executing and its output: sudo fdisk -l [sudo] password for phil: Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors 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: dos Disk identifier: 0x6058406e Device Boot Start End Sectors Size Id Type /dev/sda1 63 1012094 1012032 494.2M 83 Linux /dev/sda2 1026048 1348251647 1347225600 642.4G 5 Extended /dev/sda3 * 1348251648 1953523711 605272064 288.6G 7 HPFS/NTFS/exFAT /dev/sda5 1244766208 1314039807 69273600 33G 83 Linux /dev/sda6 1314041856 1348251647 34209792 16.3G 82 Linux swap / Solaris /dev/sda7 1028096 1244764159 1243736064 593.1G 83 Linux Partition 2 does not start on physical sector boundary. Partition table entries are not in disk order. According to my online research, this warning occurs when the partition's sector doesn't start on the "right sector", as it produces speed penalties when writing. One way to identify this issue is supposedly to check if the sector is divisible by 8; if so, the partition is correct. The output above, except for the first partition, shows that all the partitions have the first sector divisible by 8, i.e. the Extended Partition 2 and its logical partitions. Am I correct about that? And if so, why am I receiving this warning? EDIT I don't have any encripted partition (neither in linux nor in windows). The version of fdisk is: sudo fdisk -version fdisk from util-linux 2.25.2

I have 8GB flash memory stick. Sometimes ago I formatted it to be able to install Windows from it. I can't remember what exactly I did but I think I wanted to be able to install Win 7 64-bit to boot in EFI mode. Now I can't reformat it nor in Windows nor in Linux. I tried to convert it to MBR from GPT with gdisk by gdisk /dev/sdc, then w (to write GPT from memory to the drive as the tool reported "Found invalid GPT and valid MBR; converting MBR to GPT format in memory"). Then gdisk /dev/sdc again: # gdisk /dev/sdc GPT fdisk (gdisk) version 0.8.8 Partition table scan: MBR: MBR only BSD: not present APM: not present GPT: not present *************************************************************** Found invalid GPT and valid MBR; converting MBR to GPT format in memory. THIS OPERATION IS POTENTIALLY DESTRUCTIVE! Exit by typing 'q' if you don't want to convert your MBR partitions to GPT format! *************************************************************** , opened expert tools with x, z (to destroy GPT). Here is the output: Expert command (? for help): z About to wipe out GPT on /dev/sdc. Proceed? (Y/N): Y GPT data structures destroyed! You may now partition the disk using fdisk or other utilities. Blank out MBR? (Y/N): Y # then tried to delete a partition with fdisk # fdisk /dev/sdc Command (m for help): p Disk /dev/sdc: 8086 MB, 8086618112 bytes 249 heads, 62 sectors/track, 1023 cylinders, total 15794176 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000a07ca Device Boot Start End Blocks Id System /dev/sdc1 * 62 15793073 7896506 7 HPFS/NTFS/exFAT Command (m for help): d Selected partition 1 Command (m for help): p Disk /dev/sdc: 8086 MB, 8086618112 bytes 249 heads, 62 sectors/track, 1023 cylinders, total 15794176 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000a07ca Device Boot Start End Blocks Id System Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Error closing file After this I tried to pull out and plug in the stick again but NTFS mount error window appeared each time. I also tried to rewrite an initial drive area with a test content with badblocks sudo badblocks -w -s -o /tmp/usbstick.log /dev/sdc and with dd sudo dd if=/dev/zero of=/dev/sdc bs=1024k count=2 but I couldn't reformat it to usable state. Is there a way I can restore its factory state? My system: Linux Mint 17.3 **UPDATE** # blkid /dev/sdc1: UUID="675599A00CE338FC" TYPE="ntfs" # usb-devices T: Bus=01 Lev=01 Prnt=01 Port=03 Cnt=02 Dev#= 4 Spd=480 MxCh= 0 D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 P: Vendor=1307 ProdID=0190 Rev=01.00 S: Manufacturer=USBest Technology S: Product=USB Mass Storage Device S: SerialNumber=00000000000004 C: #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=98mA I: If#= 0 Alt= 0 #EPs= 3 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage

I want to install Debian (actually Open Media Server, a derivative) by using a Mac laptop (EFI) on a disk (connected via USB), to then transfer it to an headless machine already installed and configured, but the target machine doesn't support EFI, so I want to stick to MBR. Is it possible to achieve this with the current Debian 11 installer? During the installation process, there was no prompt for it, and EFI was selected, even when I manually created an MBR partition on the disk. I saw [this old question](https://unix.stackexchange.com/questions/518377/where-does-the-debian-installer-choose-mbr-vs-gpt) , but it doesn't really answer

I have a an original Windows 7 Professional x86 iso file, straight from Microsoft. I want to make a bootable USB from this ISO. Some sources suggest that I simply dd the iso to the USB, but I don't see how that should work. The ISO's first 32768 bytes (reserved as System Area on ISO 9660 media, to be used fx for MBR) are all zeroes, so there is no MBR or anything for the BIOS to read. So as far as I can understand, one way is to add a MBR in this System Area, so that the ISO can be both dd'ed to a USB or written to an optical media, and be bootable from both. I think the tool isohybrid should do that trick. I don't know how it works, so I can't figure out if it should just work for all bootable (ie bootable if written to optical media) ISO 9660 files. Or does it only work for some specific/familiar iso files? At least I can't make it work with my Windows 7 iso. I get the following error: $ isohybrid win7.iso isohybrid: win7.iso: unexpected boot catalogue parameters

I followed the very detailed guide for making hybrid MBR record (GPT/MBR) taken from here Now, gdisk says I have hybrid mbr. But I can only boot in UEFI and cannot do that in BIOS (I use external hard drive). Seems that simple execution of grub-install installs only uefi part. I saw the discussion about requirement for protective entry to be the first on the disk, so I made it the first and that is not the root cause. So the question is how to install GRUB so it would boot OS both being started from BIOS/MBR and UEFI/GPT? **$ sudo gdisk /dev/sdd** GPT fdisk (gdisk) version 1.0.1 Partition table scan: MBR: hybrid BSD: not present APM: not present GPT: present Found valid GPT with hybrid MBR; using GPT. Command (? for help): r Recovery/transformation command (? for help): o Disk size is 468862128 sectors (223.6 GiB) MBR disk identifier: 0x7213C4A0 MBR partitions: Number Boot Start Sector End Sector Status Code 1 1 208895 primary 0xEE 2 * 208896 1196031 primary 0x83 3 1196032 135413759 primary 0x83 4 200425472 468860927 primary 0x83 Recovery/transformation command (? for help): p Disk /dev/sdd: 468862128 sectors, 223.6 GiB Logical sector size: 512 bytes Disk identifier (GUID): 21773ad9-3d43-4832-85b7-6c841d20ce75 Partition table holds up to 128 entries First usable sector is 34, last usable sector is 468862094 Partitions will be aligned on 1-sector boundaries Total free space is 62183 sectors (30.4 MiB) Number Start (sector) End (sector) Size Code Name 1 63 80324 39.2 MiB EF00 Basic data partition 2 208896 1196031 482.0 MiB 8300 Basic data partition 3 1196032 135413759 64.0 GiB 8300 4 135413760 168968191 16.0 GiB 0700 Basic data partition 5 168968192 200425471 15.0 GiB 0700 Basic data partition 6 200425472 468860927 128.0 GiB 8300 7 81920 149503 33.0 MiB EF02 **$ sudo parted /dev/sdd** GNU Parted 3.2 Using /dev/sdd Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) print Model: ATA OCZ-VECTOR150 (scsi) Disk /dev/sdd: 240GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 32.3kB 41.1MB 41.1MB fat32 Basic data partition boot, esp 7 41.9MB 76.5MB 34.6MB bios_grub 2 107MB 612MB 505MB ext4 Basic data partition 3 612MB 69.3GB 68.7GB ext4 4 69.3GB 86.5GB 17.2GB linux-swap(v1) Basic data partition msftdata 5 86.5GB 103GB 16.1GB ntfs Basic data partition msftdata 6 103GB 240GB 137GB ext4 **$ sudo grub-install** Installing for x86_64-efi platform. Installation finished. No error reported.

I keep receiving this error: > Warning!! Unsupported GPT (GUID Partition Table) detected. Use GNU Parted I want to go back to the normal MBR. I found some advice [here](http://lukas.zapletalovi.com/2011/12/how-to-get-rid-of-guid-partition-table.html) and did: parted /dev/sda mklabel msdos quit But when I get to the mklabel option it spits out a warning that I will lose all data on /dev/sda. Is there a way to get the normal MBR back without formatting the disk?

I have an old laptop which I am trying to install OpenStep 4.2 with Patch 3 pack (Which supports over 8GB and has a VESA driver) on to a 2003 laptop which is a 32-bit pentium 4 with 512MB RAM and a ICH4M IDE adapter hard drive controller which is backwards compatible with the PIIX4 controller driver (I've hex edited the PCI identifier strings for PIIX4 and changed them to my ICH4M which works). I had to use Virtual Box to create a hard disk image as my laptop does not have floppy disks to read drivers before reading of the CD-ROM. I managed to create 2.88MB bootable image on VirtualBox and then boot the floppy image of one of the GRUB frameworks that allows booting of disk images or .iso's (I forgot what one it was). This still could not detect the writeable DVD drive and boot the OpenStep CD-ROM. The Open Step Virtual Box image is a 512MB flat image and I've managed to **/bin/dd** to my 40GB hard drive with C/H/S 16,383/16/63 which from research is LBA and the driver uses IDE command **IDENTIFY** to read the hard drive size. **The question is how do I manually edit the MBR so that it shows up as one 512MB partition on the HDD?** Currently at the moment nothing is showing up. I have access to Lubuntu which when you use the Partition Manage it just shows a empty drive. The Open Step image kind of works at the moment the IDE driver is having trouble as it does not detect my DVD-ROM drive (Which is ok for now). But I want to be able to create a DOS/FAT partition on the drive so I can transfer files between another OS that I want to install on the HDD. No Nextstep, Openstep tags. --- In Response to user Marcus Müller who posted comments. I have used the page you mentioned to create a bootable CD which is how I managed to make a custom 2.88MB disk image that I can boot of USB using the GRUB floppy disk image booter. The main problem seems to be the EIDE.config driver (V3.337 which supports PIIX IDE hardware, the ICH4M is backwards compatible with PIIX IDE hardware as per ICH4M IDE documentation manual) seems to keep showing a error.

`
PCI bus support enabled
PnP: Plug and Play support enabled
PnP: Plug and Play BIOS present
PnP: read port 0x0, max csn 0
ISA/EISA bus support enabled
ISA bus
DriverKit version 420
BusLogic Board not found at port 0x330
Registering: PS2Controller
Registering: PCKeyboard0
Registering: PCMCIA0
PCI bus support enabled
Registering: PCI0
Registering: EISA0
hc0: device detected at port 0x1f0 irq 14
hc0: drive 0, type 55, using geometry from INT table.
hc0: WARNING: using disk geomtry for drive 0.
hc0: Checking for ATA drive 0...
hc0: drive 0, type 55, using geometry from INT table.
hc0: WARNING: using BIOS geometry for drive 0.
hc0: Resetting drives..
Registering: hc0
hd0: 1024 cylinders, 255 heads, 63 spt
hd0: using single sector transfers.
Registering: hd0
hc0: ATA command 20 failed. Retrying...	; 0x20 READ_SECTORS
hc0: ATA Command: error=0x1 secCnt=0x1 secNum=0x1 cyl=0xeb14 drhd=0xe0 status=0x0
hc0: Resetting drives..
hc0: ATA command 20 failed. Retrying...
hc0: ATA Command: error=0x1 secCnt=0x1 secNum=0x1 cyl=0xeb14 drhd=0xe0 status=0x0
hc0: Resetting drives..
hc0: ATA command 20 failed. Retrying...
hc0: ATA Command: error=0x1 secCnt=0x1 secNum=0x1 cyl=0xeb14 drhd=0xe0 status=0x0
hc0: Resetting drives..

` So I'm wondering if this conflicting error with HD image as the image I created on Virtual Box says the HD is only 512MB but the HD is saying to the controller it's 60GB. So I was wanting help with writing to the MBR that the first partition will only be the first 512MB of the HDD and that the rest is available. The EIDE/ATAPI driver can not detect my DVD ROM so can't read the CD otherwise I would install of the CD-ROM.

I've got a disk image that I need shortened slightly (long story - but it deals with variances in flash drive sizes). The partitions are *already* short enough, but the drive size is not. Basically, I have a disk image that is 15678308352 bytes (30621696 sectors). I'm wanting to reduce the disk image size to 15678292992 bytes (30621666 sectors). The last sector being used by any "real" partition is 30621662 (I'm fine ending there, too, but I padded it by 4 sectors just to be safe). In any case, I'm wanting to resize the partition tables, but I don't really know how, especially since the GPT table is inside a "protected MBR". Here's the output of fdisk showing the protected MBR:

fdisk mydisk.img 
Disk: mydisk.img	geometry: 1906/255/63 [30621696 sectors]
Signature: 0xAA55
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 1: EE    0   0   2 - 1023 255  63 [         1 -   30621695] 
 2: 00    0   0   0 -    0   0   0 [         0 -          0] unused      
 3: 00    0   0   0 -    0   0   0 [         0 -          0] unused      
 4: 00    0   0   0 -    0   0   0 [         0 -          0] unused

Here's the output of gdisk showing the GPT info:

GPT fdisk (gdisk) version 1.0.10

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present


Found valid GPT with protective MBR; using GPT.

Command (? for help): p
Disk mydisk.img: 30621696 sectors, 14.6 GiB
Sector size (logical): 512 bytes
Disk identifier (GUID): BD99B4B8-8070-0648-AEA4-B28BCD949EB7
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 30621662
Partitions will be aligned on 2048-sector boundaries
Total free space is 18398 sectors (9.0 MiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            8192          249855   118.0 MiB   8300  primary
   2          260096        30621662   14.5 GiB    8300  primary

As you can see, I have plenty of room to shrink the disk but I just don't know how. I tried manually editing the MBR partition size in hexedit, but then I got all sorts of warnings on the GPT partition. Any ideas?

I am reading through the UEFI standard . On page 115, section 5 it discusses the GPT disk layout. I'm a bit confused as to exactly how this works. From the below, it sounds like UEFI will ignore the MBR. > A legacy MBR may be located at LBA 0 (i.e., the first logical block) > of the disk if it is not using the GPT disk layout (i.e., if it is > using the MBR disk layout). The boot code on the MBR is not executed > by UEFI firmware. So is this basically saying if you put the firmware in legacy boot mode, this is how to define an MBR which will play nicely with that legacy boot mode? Am I correct in saying that if the system's firmware were in UEFI mode, then a system with an MBR defined as specified in chapter 5 would not be bootable?

I currently have Windows and Arch Linux installed on a drive with a GPT partition and grub. I am now trying to install Linux Mint alongside these two. I am installing Mint on a second HDD (same PC) with an MBR partition and I am having trouble running the installed OS. I have tried adding it—not together, but in different tries—to both EFI (one in the GPT partition and one in the MBR partition) and both are giving errors. The errors are "load kernel first, msdos not found". I will try to attach a screenshot. It comes at startup when I try to boot Linux Mint from grub. I have tried everything. I can't format the entire second disk to GPT since I have data in other partitions of the disk. Any help would be appreciated. I have tried changing boot to legacy, it also didn't work. There seems to be a tool, mbr2gpt but I can't get it to work. I have no OS other than Linux Mint (installing) in the second HDD. I don't know if its gpt issue or something else. Ubuntu also seems to have issue. It said some error like not authorized to access grub in gpt. I have tried to install grub in mbr but it seems to overwrite grub with gpt and I couldn't login to arch. Edit1:- This is the error on selecting linuxmint from grub Edit2:-Adding boot-info from boot repair

boot-repair-4ppa200                                              [20240525_2040]

============================== Boot Info Summary ===============================

 => Grub2 (v2.00) is installed in the MBR of /dev/sda and looks at sector 1 of
    the same hard drive for core.img. core.img is at this location and looks
    for (,msdos3)/boot/grub. It also embeds following components:
   
    modules
    ---------------------------------------------------------------------------
    fshelp ext2 part_msdos biosdisk
    ---------------------------------------------------------------------------
 => No boot loader is installed in the MBR of /dev/sdb.
 => Syslinux MBR (5.00 and higher) is installed in the MBR of /dev/sdc.

sda1: __________________________________________________________________________

    File system:       vfat
    Boot sector type:  FAT32
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        

sda2: __________________________________________________________________________

    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:        

sda3: __________________________________________________________________________

    File system:       Extended Partition
    Boot sector type:  -
    Boot sector info:

sda5: __________________________________________________________________________

    File system:       ext4
    Boot sector type:  -
    Boot sector info:
    Operating System:  LMDE 6 (faye)
    Boot files:        /etc/fstab /etc/default/grub

sda6: __________________________________________________________________________

    File system:       ext4
    Boot sector type:  -
    Boot sector info:
    Operating System:  
    Boot files:        

sda7: __________________________________________________________________________

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

sda4: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 7/2008: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        

sdb1: __________________________________________________________________________

    File system:       vfat
    Boot sector type:  Windows 7/2008: FAT32
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        /efi/Boot/bootx64.efi /efi/GRUB/grubx64.efi
                       /efi/Microsoft/Boot/bootmgfw.efi
                       /efi/Microsoft/Boot/bootmgr.efi

sdb2: __________________________________________________________________________

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

sdb3: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 7/2008: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  Windows 8 or 10
    Boot files:        /Windows/System32/winload.exe

sdb4: __________________________________________________________________________

    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:        

sdb5: __________________________________________________________________________

    File system:       ext4
    Boot sector type:  -
    Boot sector info:
    Operating System:  Arch Linux
    Boot files:        /boot/grub/grub.cfg /etc/fstab /etc/default/grub

sdb6: __________________________________________________________________________

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

sdc1: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  SYSLINUX 6.04
    Boot sector info:  Syslinux looks at sector 44096 of /dev/sdc1 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 /ldlinux.sys

sdc2: __________________________________________________________________________

    File system:       vfat
    Boot sector type:  FAT16
    Boot sector info:  According to the info in the boot sector, sdc2 starts
                       at sector 0. But according to the info from fdisk,
                       sdc2 starts at sector 61437880. According to the info
                       in the boot sector, sdc2 has 0 sectors.
    Operating System:  
    Boot files:        /efi/Boot/bootaa64.efi /efi/Boot/bootarm.efi
                       /efi/Boot/bootia32.efi /efi/Boot/bootx64.efi
                       /efi/Rufus/exfat_aa64.efi /efi/Rufus/exfat_arm.efi
                       /efi/Rufus/exfat_ia32.efi /efi/Rufus/exfat_x64.efi
                       /efi/Rufus/ntfs_aa64.efi /efi/Rufus/ntfs_arm.efi
                       /efi/Rufus/ntfs_ia32.efi /efi/Rufus/ntfs_x64.efi


================================ 3 OS detected =================================

OS#1:   LMDE 6 (faye) on sda5
OS#2:   Arch Linux on sdb5
OS#3:   Windows 8 or 10 on sdb3

================================ Host/Hardware =================================

CPU architecture: 64-bit
Video: 4th Gen Core Processor Integrated Graphics Controller from Intel Corporation
Live-session OS is Linuxmint 64-bit (LMDE 6 (faye), faye, x86_64)

===================================== UEFI =====================================

BIOS/UEFI firmware: 79CN46WW(V3.05)(1.70) 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: 0000
Timeout: 2 seconds
BootOrder: 0003,0002,2001,2002,2003
Boot0000* EFI USB Device (Generic Flash Disk) PciRoot(0x0)/Pci(0x14,0x0)/USB(0,0)/HD(2,MBR,0x29c46,0x3a977b8,0x800)RC
Boot0002* Windows Boot Manager HD(1,GPT,d51273d0-888f-4ca8-9490-a9ba15966eae,0x7d800,0x32000)/File(\EFI\MICROSOFT\BOOT\BOOTMGFW.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.}...a............. ...
Boot0003* GRUB HD(1,GPT,d51273d0-888f-4ca8-9490-a9ba15966eae,0x7d800,0x32000)/File(\EFI\GRUB\grubx64.efi)
Boot2001* EFI USB Device RC
Boot2002* EFI DVD/CDROM RC
Boot2003* EFI Network RC

04fb9982cb9d93492d3220cf08f03f02   sdb1/Boot/bootx64.efi
a2418029711ac3b3e3bfd27223a1fb6d   sdb1/GRUB/grubx64.efi
04fb9982cb9d93492d3220cf08f03f02   sdb1/Microsoft/Boot/bootmgfw.efi
8ea8644096bf0b8227e6541e9a790f8c   sdb1/Microsoft/Boot/bootmgr.efi
e099b8f8463ef839720fda267e70eeb1   sdc2/Boot/bootaa64.efi
cfd0ce50df258fc747f5753ecf6ec312   sdc2/Boot/bootarm.efi
19a65a943434a625a53490391fa28349   sdc2/Boot/bootia32.efi
3fdfc83db7958b2eac1e720334f12147   sdc2/Boot/bootx64.efi
4a4e8e66e0d3712f19d964a7bca4fafc   sdc2/Rufus/exfat_aa64.efi
93f66a43d49990f986a81c67843d66a5   sdc2/Rufus/exfat_arm.efi
3c5f23f198267df4a64fe2a3587039e7   sdc2/Rufus/exfat_ia32.efi
81d015f35982a0bbf4056f09a2eca39a   sdc2/Rufus/exfat_x64.efi
a03e27b0e7f2e03519166bf6b41f68c5   sdc2/Rufus/ntfs_aa64.efi
2f31c70d3f4235476cd9ed6a18e13221   sdc2/Rufus/ntfs_arm.efi
7e7e67c33ce9ff2961a4be4080d23352   sdc2/Rufus/ntfs_ia32.efi
30c7e0752040cf5e31843d897a53e055   sdc2/Rufus/ntfs_x64.efi

============================= Drive/Partition Info =============================

Disks info: ____________________________________________________________________

sdb : is-GPT, no-BIOSboot, has---ESP, not-usb, not-mmc, has-os, has-win, 2048 sectors * 512 bytes
sdc : notGPT, no-BIOSboot, has---ESP, usb-disk, not-mmc, no-os, no-wind, 2048 sectors * 512 bytes
sda : notGPT, no-BIOSboot, has-noESP, not-usb, not-mmc, has-os, no-wind, 2048 sectors * 512 bytes

Partitions info (1/3): _________________________________________________________

sdb4 : no-os, 32, nopakmgr, no-docgrub, nogrub, nogrubinstall, no-grubenv, noupdategrub, farbios
sdb5 : is-os, 64, pacman, no-docgrub, grub2, grub-install, grubenv-ok, grub-mkconfig -o /boot/grub, farbios
sdb3 : is-os, 32, nopakmgr, no-docgrub, nogrub, nogrubinstall, no-grubenv, noupdategrub, farbios
sdb1 : no-os, 32, nopakmgr, no-docgrub, nogrub, nogrubinstall, no-grubenv, noupdategrub, not-far
sdc2 : no-os, 32, nopakmgr, no-docgrub, nogrub, nogrubinstall, no-grubenv, noupdategrub, not-far
sda4 : no-os, 32, nopakmgr, no-docgrub, nogrub, nogrubinstall, no-grubenv, noupdategrub, farbios
sda2 : no-os, 32, nopakmgr, no-docgrub, nogrub, nogrubinstall, no-grubenv, noupdategrub, not-far
sda5 : is-os, 64, apt-get, grub-pc , grub2, grub-install, no-grubenv, update-grub, not-far
sda1 : no-os, 32, nopakmgr, no-docgrub, nogrub, nogrubinstall, no-grubenv, noupdategrub, not-far
sda6 : no-os, 32, nopakmgr, no-docgrub, nogrub, nogrubinstall, no-grubenv, noupdategrub, not-far

Partitions info (2/3): _________________________________________________________

sdb4 : isnotESP, part-has-no-fstab, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot
sdb5 : isnotESP, fstab-without-efi, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot
sdb3 : isnotESP, part-has-no-fstab, no-nt, haswinload, no-recov-nor-hid, no-bmgr, notwinboot
sdb1 : is---ESP, part-has-no-fstab, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot
sdc2 : 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, no-winload, no-recov-nor-hid, no-bmgr, notwinboot
sda2 : isnotESP, part-has-no-fstab, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot
sda5 : 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, no-recov-nor-hid, no-bmgr, notwinboot
sda6 : isnotESP, part-has-no-fstab, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot

Partitions info (3/3): _________________________________________________________

sdb4 : not--sepboot, no---boot, part-has-no-fstab, not-sep-usr, no---usr, part-has-no-fstab, no--grub.d, sdb
sdb5 : not--sepboot, with-boot, fstab-without-boot, not-sep-usr, with--usr, fstab-without-usr, std-grub.d, sdb
sdb3 : not--sepboot, no---boot, part-has-no-fstab, not-sep-usr, no---usr, part-has-no-fstab, no--grub.d, sdb
sdb1 : not--sepboot, no---boot, part-has-no-fstab, not-sep-usr, no---usr, part-has-no-fstab, no--grub.d, sdb
sdc2 : not--sepboot, no---boot, part-has-no-fstab, not-sep-usr, no---usr, part-has-no-fstab, no--grub.d, sdc
sda4 : 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
sda5 : not--sepboot, with-boot, fstab-without-boot, not-sep-usr, with--usr, fstab-without-usr, std-grub.d, sda
sda1 : is---sepboot, no---boot, part-has-no-fstab, not-sep-usr, no---usr, part-has-no-fstab, no--grub.d, sda
sda6 : maybesepboot, no---boot, part-has-no-fstab, not-sep-usr, no---usr, part-has-no-fstab, no--grub.d, sda

fdisk -l (filtered): ___________________________________________________________

Disk sda: 232.89 GiB, 250059350016 bytes, 488397168 sectors
Disk identifier: 0xf638964d
      Boot     Start       End   Sectors   Size Id Type
sda1            2048    206847    204800   100M  7 HPFS/NTFS/exFAT
sda2          206848  39266303  39059456  18.6G  7 HPFS/NTFS/exFAT
sda3        39270398 205006847 165736450    79G  5 Extended
sda4       205006848 488392703 283385856 135.1G  7 HPFS/NTFS/exFAT
sda5        39272448  72040447  32768000  15.6G 83 Linux
sda6        72042496 135530495  63488000  30.3G 83 Linux
sda7       135532544 146796543  11264000   5.4G 82 Linux swap / Solaris
Partition table entries are not in disk order.
Disk sdb: 447.13 GiB, 480103981056 bytes, 937703088 sectors
Disk identifier: 3DAEA9F5-FE33-4404-8FF7-EFDA8914769F
          Start       End   Sectors   Size Type
sdb1     514048    718847    204800   100M EFI System
sdb2     718848    751615     32768    16M Microsoft reserved
sdb3     751616 512751615 512000000 244.1G Microsoft basic data
sdb4  512751616 753379327 240627712 114.7G Microsoft basic data
sdb5  753379328 921151487 167772160    80G Linux filesystem
sdb6  921151488 937701375  16549888   7.9G Linux swap
Disk sdc: 29.3 GiB, 31457280000 bytes, 61440000 sectors
Disk identifier: 0x00029c46
      Boot    Start      End  Sectors  Size Id Type
sdc1  *        2048 61437879 61435832 29.3G  7 HPFS/NTFS/exFAT
sdc2       61437880 61439927     2048    1M ef EFI (FAT-12/16/32)

parted -lm (filtered): _________________________________________________________

sda:250GB:scsi:512:512:msdos:ATA TOSHIBA MK2555GS:;
1:1049kB:106MB:105MB:fat32::;
2:106MB:20.1GB:20.0GB:ntfs::;
3:20.1GB:105GB:84.9GB:::;
5:20.1GB:36.9GB:16.8GB:ext4::;
6:36.9GB:69.4GB:32.5GB:ext4::;
7:69.4GB:75.2GB:5767MB:linux-swap(v1)::swap;
4:105GB:250GB:145GB:ntfs::;
sdb:480GB:scsi:512:512:gpt:ATA GIGABYTE GP-GSTF:;
1:263MB:368MB:105MB:fat32:EFI system partition:boot, esp;
2:368MB:385MB:16.8MB::Microsoft reserved partition:msftres;
3:385MB:263GB:262GB:ntfs:Basic data partition:msftdata;
4:263GB:386GB:123GB:ntfs:Basic data partition:msftdata;
5:386GB:472GB:85.9GB:ext4::;
6:472GB:480GB:8474MB:linux-swap(v1)::swap;
sdc:31.5GB:scsi:512:512:msdos:Generic Flash Disk:;
1:1049kB:31.5GB:31.5GB:ntfs::boot;
2:31.5GB:31.5GB:1049kB:::esp;

Free space >10MiB: ______________________________________________________________

sda: 71678MiB:100101MiB:28423MiB
sdb: 0.02MiB:251MiB:251MiB

blkid (filtered): ______________________________________________________________

NAME   FSTYPE   UUID                                 PARTUUID                             LABEL                  PARTLABEL
sda                                                                                                              
├─sda1 vfat     5723-D062                            f638964d-01                                                
├─sda2 ntfs     267C88077C87CFCB                     f638964d-02                          New Volume            
├─sda3                                               f638964d-03                                                
├─sda4 ntfs     DC8C86758C8649CA                     f638964d-04                          New Volume            
├─sda5 ext4     36e0d91a-caa4-40b8-bd15-d264910228dd f638964d-05                                                
├─sda6 ext4     e9f531a4-b065-4a8c-a0d3-756b486e5d84 f638964d-06                                                
└─sda7 swap     35401696-3044-46b3-82f3-d6eb6e9151a9 f638964d-07                                                
sdb                                                                                                              
├─sdb1 vfat     3416-50EE                            d51273d0-888f-4ca8-9490-a9ba15966eae                        EFI system partition
├─sdb2                                               751b43fb-bbae-402c-87ef-8a8745bb3804                        Microsoft reserved partition
├─sdb3 ntfs     FCB040C8B0408ADA                     fb0cea09-889d-43f1-89a1-e6ea4e84b376                        Basic data partition
├─sdb4 ntfs     3894A28694A2466A                     97dcb553-4f8a-4b44-9e73-8176de7968ce New Volume             Basic data partition
├─sdb5 ext4     959afc21-ab26-4c23-82b1-cd4ad6afb826 82c37fd0-5918-437f-af1e-ad9d408c52f9                        
└─sdb6 swap     302c29c8-cfc0-43af-a5ac-49ecb572b079 57783657-fb60-47ae-befe-2f8b2780c769                        
sdc                                                                                                              
├─sdc1 ntfs     64D05309D052E0BA                     00029c46-01                          LMDE 6 Cinnamon 64-bit
└─sdc2 vfat     5FA3-F2DA                            00029c46-02                          UEFI_NTFS              

Mount points (filtered): _______________________________________________________

              Avail Use% Mounted on
/dev/sda1         0 100% /mnt/boot-sav/sda1
/dev/sda2        1G  94% /mnt/boot-sav/sda2
/dev/sda4        7G  95% /mnt/boot-sav/sda4
/dev/sda5      7.4G  46% /mnt/boot-sav/sda5
/dev/sda6     28.1G   0% /mnt/boot-sav/sda6
/dev/sdb1     68.5M  29% /mnt/boot-sav/sdb1
/dev/sdb3    175.7G  28% /mnt/boot-sav/sdb3
/dev/sdb4     44.5G  61% /mnt/boot-sav/sdb4
/dev/sdb5       40G  44% /mnt/boot-sav/sdb5
/dev/sdc1     26.7G   9% /run/live/medium
/dev/sdc1     26.7G   9% /usr/lib/live/mount/medium
/dev/sdc2      126K  87% /mnt/boot-sav/sdc2
overlay        1.8G   5% /

Mount options (filtered): ______________________________________________________

/dev/sda1    vfat            rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro
/dev/sda2    fuseblk         rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
/dev/sda4    fuseblk         rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
/dev/sda5    ext4            rw,relatime
/dev/sda6    ext4            rw,relatime
/dev/sdb1    vfat            rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro
/dev/sdb3    fuseblk         rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
/dev/sdb4    fuseblk         rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
/dev/sdb5    ext4            rw,relatime
/dev/sdc1    fuseblk         rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
/dev/sdc1    fuseblk         rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
/dev/sdc2    vfat            rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro

==================== sda1: Location of files loaded by Grub ====================

           GiB - GB             File                                 Fragment(s)
            ?? = ??             vmlinuz-6.1.0-12-amd64                         1
            ?? = ??             initrd.img-6.1.0-12-amd64                      2
            ?? = ??             initrd.img-6.1.0-12-amd64.dpkg-bak             2

========================== sda5/etc/fstab (filtered) ===========================

proc /proc proc defaults 0 0
UUID=3416-50EE /boot/efi vfat defaults 0 1
UUID=36e0d91a-caa4-40b8-bd15-d264910228dd / ext4 rw,errors=remount-ro 0 1
UUID=35401696-3044-46b3-82f3-d6eb6e9151a9 swap swap sw 0 0
UUID=e9f531a4-b065-4a8c-a0d3-756b486e5d84 /home ext4 rw,errors=remount-ro 0 0

======================= sda5/etc/default/grub (filtered) =======================

GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR=lsb_release -i -s 2> /dev/null || echo Debian
GRUB_CMDLINE_LINUX_DEFAULT="quiet"
GRUB_CMDLINE_LINUX=""

==================== sda5: Location of files loaded by Grub ====================

           GiB - GB             File                                 Fragment(s)
  28.007579803 = 30.072909824   boot/vmlinuz-6.1.0-12-amd64                    1
  28.007579803 = 30.072909824   vmlinuz                                        1
  28.007579803 = 30.072909824   vmlinuz.old                                    1
  29.340026855 = 31.503613952   boot/initrd.img-6.1.0-12-amd64                 1
  29.340026855 = 31.503613952   initrd.img                                     1
  29.340026855 = 31.503613952   initrd.img.old                                 1

===================== sda5: ls -l /etc/grub.d/ (filtered) ======================

-rwxr-xr-x 1 root root 14123 Apr 23  2023 10_linux
-rwxr-xr-x 1 root root 14180 Apr 23  2023 20_linux_xen
-rwxr-xr-x 1 root root 12923 Apr 23  2023 30_os-prober
-rwxr-xr-x 1 root root  1372 Apr 23  2023 30_uefi-firmware
-rwxr-xr-x 1 root root   722 Feb 26  2023 35_fwupd
-rwxr-xr-x 1 root root   214 Apr 23  2023 40_custom
-rwxr-xr-x 1 root root   215 Apr 23  2023 41_custom

=========================== sda5/etc/grub.d/35_fwupd ===========================

#! /bin/sh
# SPDX-License-Identifier: LGPL-2.1+
set -e
[ -d ${pkgdatadir:?} ]
# shellcheck source=/dev/null
. "$pkgdatadir/grub-mkconfig_lib"
if [ -f /var/lib/fwupd/uefi_capsule.conf ] &&
   ls /sys/firmware/efi/efivars/fwupd-*-0abba7dc-e516-4167-bbf5-4d9d1c739416 1>/dev/null 2>&1; then
      . /var/lib/fwupd/uefi_capsule.conf
      if [ "${EFI_PATH}" != "" ] && [ "${ESP}" != "" ]; then
      echo "Adding Linux Firmware Updater entry" >&2
cat  /dev/null
      prepare_grub_to_access_device "$(${grub_probe} --target=device ${ESP})" | sed -e "s/^/\t/"
cat      
UUID=959afc21-ab26-4c23-82b1-cd4ad6afb826 /         ext4       rw,relatime 0 1
UUID=3416-50EE       /efi       vfat       rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro 0 2
UUID=302c29c8-cfc0-43af-a5ac-49ecb572b079 none       swap       defaults   0 0

======================= sdb5/etc/default/grub (filtered) =======================

GRUB_DEFAULT=0
GRUB_TIMEOUT=-1
GRUB_DISTRIBUTOR="Arch"
GRUB_CMDLINE_LINUX_DEFAULT="loglevel=3 quiet"
GRUB_CMDLINE_LINUX=""
GRUB_PRELOAD_MODULES="part_gpt part_msdos"
GRUB_TIMEOUT_STYLE=menu
GRUB_TERMINAL_INPUT=console
GRUB_GFXMODE=auto
GRUB_GFXPAYLOAD_LINUX=keep
GRUB_DISABLE_RECOVERY=true
GRUB_DISABLE_OS_PROBER=false

==================== sdb5: Location of files loaded by Grub ====================

           GiB - GB             File                                 Fragment(s)
 433.167007446 = 465.109532672  boot/grub/grub.cfg                             1
 384.229732513 = 412.563533824  boot/vmlinuz                                   1
 379.989253998 = 408.010354688  boot/vmlinuz-linux                             2
 395.520416260 = 424.686813184  boot/vmlinuz.old                               1
 427.176753998 = 458.677547008  boot/initramfs-linux-fallback.img             12
 365.950191498 = 392.936026112  boot/initramfs-linux.img                       2

===================== sdb5: ls -l /etc/grub.d/ (filtered) ======================

-rwxr-xr-x 1 root root 12579 Mar 16 19:09 10_linux
lrwxrwxrwx 1 root root    34 May 18 14:48 15_ostree -> /usr/lib/libostree/grub2-15_ostree
-rwxr-xr-x 1 root root 14341 Mar 16 19:09 20_linux_xen
-rwxr-xr-x 1 root root   786 Mar 16 19:09 25_bli
-rwxr-xr-x 1 root root 12289 Mar 16 19:09 30_os-prober
-rwxr-xr-x 1 root root  1174 Mar 16 19:09 30_uefi-firmware
-rwxr-xr-x 1 root root   214 Mar 16 19:09 40_custom
-rwxr-xr-x 1 root root   215 Mar 16 19:09 41_custom

============================ sdb5/etc/grub.d/25_bli ============================

#! /bin/sh
set -e
# grub-mkconfig helper script.
# Copyright (C) 2023  Free Software Foundation, Inc.
#
# GRUB is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# GRUB is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GRUB.  If not, see .
cat << EOF
if [ "\$grub_platform" = "efi" ]; then
  insmod bli
fi
EOF

====================== sdc1/boot/grub/grub.cfg (filtered) ======================

Start LMDE 6 64-bit
Start LMDE 6 64-bit (compatibility mode)
Boot from next volume
UEFI Firmware Settings
Memory test

========================= sdc1/syslinux.cfg (filtered) =========================

DEFAULT loadconfig

LABEL loadconfig
  CONFIG /isolinux/isolinux.cfg
  APPEND /isolinux/

==================== sdc1: Location of files loaded by Grub ====================

           GiB - GB             File                                 Fragment(s)
            ?? = ??             boot/grub/grub.cfg

================== sdc1: Location of files loaded by Syslinux ==================

           GiB - GB             File                                 Fragment(s)
            ?? = ??             syslinux.cfg
            ?? = ??             ldlinux.sys                                    1



Suggested repair: ______________________________________________________________

The default repair of the Boot-Repair utility would purge (in order to fix packages) and reinstall the grub-efi of
sda5,
using the following options:  sdb1/boot/efi
Additional repair would be performed: unhide-bootmenu-10s use-standard-efi-file

Final advice in case of suggested repair: ______________________________________

Please do not forget to make your UEFI firmware boot on the LMDE 6 (faye) entry (sdb1/efi/****/grub****.efi (**** will be updated in the final message) 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\****\grub****.efi (**** will be updated in the final message)

Edit:- This is menu entry in grub config

menuentry 'LMDE 6 (faye) (on /dev/sdb5)' --class gnu-linux --class gnu --class os $menuentry_id_option 'osprober-gnulinux-/vmlinuz.old--36e0d91a-caa4-40b8-bd15-d264910228dd' {
		insmod part_msdos
		insmod ext2
		set root='hd1,msdos5'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd1,msdos5 --hint-efi=hd1,msdos5 --hint-baremetal=ahci1,msdos5  36e0d91a-caa4-40b8-bd15-d264910228dd
		else
		  search --no-floppy --fs-uuid --set=root 36e0d91a-caa4-40b8-bd15-d264910228dd
		fi
		linux /vmlinuz.old root=/dev/sdb5
		initrd /initrd.img.old
	}

This is the UUID in sdb5 where os is installed

/dev/sdb5: UUID="36e0d91a-caa4-40b8-bd15-d264910228dd" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="f638964d-05"

The UUID seems to be different in the error during boot. But grub config seems to be correct

I have a GPT formatted SSD Drive that I have moved from a rather new laptop to an older one that has an old BIOS. The Linux systems installed on it work fine (Kubuntu 22.04 and Mint 21), although I cannot install Windows (but that's another matter that doesn't concern us here). I want to fix the grub so that it boots into Kubuntu (set Kubuntu as the grub location). —After trying to install Windows and failing, and then trying to fix the grub with grub-repair and failing, as explained here, I have installed a supplementary Linux Mint system in order to be able to access the old one. Now I want to get rid of the second Linux, but that would make my laptop unusable unless I make Kubuntu the the default boot before or after removing Mint (which I don't know how).— With MBR drives it seemed very simple to me to use Boot Repair and fix frequent errors after installing or removing operating systems. But since a few years, with UEFI and GPT I usually end up with solutions that don't involve Boot Repair. Here, I don't want to re-format the drive and change to a MBR structure. On the other hand, changing or updating to UEFI is not an option on this machine. I get this error saying the session is in BIOS / legacy mode. Is Boot Repair only handling GPT under UEFI? --- - By the way: after taking the drive out and connecting it externally to a UEFI computer, can I use Boot Repair on that computer to set grub location on the Kubuntu 22.04 partition (on that GPT external drive) so that back on the old PC it boots as intended? — Or is thus setting grub location on a partition of an external drive going to destroy the grub configuration of the UEFI computer?

Okay, let me explain. This is a UEFI computer. It has two disks. The primary disk is partitioned with GPT and boots via GRUB2 to an Arch Linux partition. The secondary disk is partitioned with MBR and only boots if I disable the primary disk in the UEFI setup utility. The secondary disk has a partition with Windows 10. My question is how do I add a menu entry to the primary GRUB2 configuration that boots the Windows 10 partition on the secondary disk? I tried

-mkconfig

with

-prober

and it was unable to find the Windows 10 install. There's apparently nothing wrong with the Windows 10 install, since it boots just fine on its own. I then tried manually adding various menu entries to the grub.cfg but they didn't work. Below are some of the entries that I tried.

menuentry "Windows 10 (loader) (on /dev/sda3)" {
	insmod part_msdos
	insmod ntfs
	insmod ntldr

	ntldr (hd0,msdos3)/bootmgr
}

menuentry "windows 10 (loader) (on /dev/sda3) 2" {
	insmod part_msdos
	insmod ntfs
	chainloader (hd0,msdos3)+1
}

menuentry "Windows 10 (loader) (on /dev/sda3) 3" {
	insmod part_msdos
	insmod ntfs
	chainloader (hd0,msdos3)/Windows/Boot/EFI/bootmgfw.efi
}

The most successful one is the last one which apparently boots to the EFI FW program but gives a BCD error (which is not present when booting normally.)

I wanted to upgrade my 1.5TB HDD to a 4TB SSD, none of the internet resources I found correctly matched my situation from beginning to end, and I ended up spending about 20 hours getting it to work, so I'm compiling my findings here for future travelers.

I am trying to create portable grub mbr with grub-mkimage to chainload as bootsector from Windows, but when booting I get stuck at a black screen with a bold "GRUB" and a blinking cursor. There's no key response. My codes:

-mkimage -p=(hd0,msdos9)/boot --target=i386-pc -o core.img biosdisk minicmd part_msdos terminal ntfs ext2

boot.img test.mbr

if=core.img of=test.mbr bs=512 seek=1

I made this work once, but cant remember how. How can I make a grub mbr without Linux. I used busybox for dd.

How can I tell whether my harddrive is laid out using an MBR or GPT format?

I try to move all data from one SSD to another SSD. The old SSD is 500 GB, and the new SSD is 1000 GB. Firstly I've created a backup:

dd if=/dev/nvme0n1 | gzip -c /media/ubuntu/local/backup1.img.gz

Then I tried to restore the backup:

gunzip -c /media/ubuntu/local/backup1.img.gz | dd of=/dev/nvme0n1

After that, I got an error:

$ sudo e2fsck /dev/nvme0n1
e2fsck 1.46.5 (30-Dec-2021)
ext2fs_open2: Bad magic number in super-block
e2fsck: Superblock invalid, trying backup blocks...
e2fsck: Bad magic number in super-block while trying to open /dev/nvme0n1

The superblock could not be read or does not describe a valid ext2/ext3/ext4
filesystem.  If the device is valid and it really contains an ext2/ext3/ext4
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
    e2fsck -b 8193 
 or
    e2fsck -b 32768 

Found a gpt partition table in /dev/nvme0n1

Do you know how I can fix it? Additional output for details:

$ lsblk -f
NAME        FSTYPE   FSVER            LABEL                    UUID                                 FSAVAIL FSUSE% MOUNTPOINTS
sdc                                                                                                                
└─sdc1      ntfs                      local                    824A5D3E4A5D2FE1                        244G    49% /media/ubuntu/local
nvme0n1                                                                                                            
├─nvme0n1p1                                                                                                        
├─nvme0n1p2                                                                                                        
├─nvme0n1p3                                                                                                        
├─nvme0n1p4                                                                                                        
├─nvme0n1p5                                                                                                        
├─nvme0n1p6                                                                                                        
└─nvme0n1p7

All of the tools I've tried until now were only capable to create a dual (GPT & MBR) partition table, where the first 4 of the GPT partitions were mirrored to a compatible MBR partition. This is not what I want. I want a pure GPT partition table, i.e. where there isn't MBR table on the disk, and thus there isn't also any synchronizing between them. Is it somehow possible?

Trying to clean the mbr code part on a disk using the pfsense 2.7.0 live disk (pfsense is based on freebsd) under shell command. being **/dev/da0** my drive following the suggested code for clean just the mbr code keeping the partitions the command should be: dd if=/dev/zero of=/dev/da0 bs=446 count=1 however... the result is: dd: /dev/da0: Invalid argument 1+0 records in 0+0 records out 0 bytes transferred in 0.000089 secs (0 bytes/sec) instead... if I use as code just dd if=/dev/zero of=/dev/da0 it just erases everything without errors :( I'm doing this tests in a vm so I can recover the hd many times to test this passage... however this thing is giving me headaches... **EDIT:** It seems that if I use bs=512 or bs=1M it doesn't gives errors. However doing so also the partitions table part would be deleted... **EDIT2:** I tried to use the command dd if=/dev/da0 of=/tmp/mbr_file bs=512 count=1 and it create for me a file with the mbr, I wonder what commands can I use for edit in binary mode the file filling the first 446 bytes with 0 and then use dd if=/tmp/mbr_file of=/dev/da0 bs=512 count=1 to restore it. What could I use? vi?

You might think this question is trivial because an msdos partition table MBR ends with 55 AA (hex). But it's not because disks formatted as FAT32 (with no partition table) end with 55 AA too. I formatted a disk like this: mkfs.vfat -F32 /dev/sdX Such a disk has no partition table and is recognized on both Linux and Windows. The first 512 bytes end with 55 AA. How does Linux know that on such a disk there is no valid partition table even though it ends with 55 AA?

I have a Linux system with the following disk setup (MBR-formatted, BIOS-booted):

sda                                             32G disk              
└─sda1                                          32G part  crypto_LUKS 001b349b-2a70-4408-bae2-107d035c96e9
  └─luks-001b349b-2a70-4408-bae2-107d035c96e9   32G crypt btrfs       8c72adab-63cf-4526-b77e-78f11d2585e2

It works great, but I want to change the UUIDs of both the LUKS volume and the filesystem. This is because I am creating a bootable rescue USB off my main machine, and so I need to avoid UUID collisions when booted from the USB. So I try:

sudo sed -i 's/001b349b/101b349b/g' /etc/default/grub
sudo sed -i 's/001b349b/101b349b/g' /etc/fstab
sudo sed -i 's/001b349b/101b349b/g' /boot/grub/grub.cfg
sudo sed -i 's/8c72adab/7c72adab/g' /etc/default/grub
sudo sed -i 's/8c72adab/7c72adab/g' /etc/fstab
sudo sed -i 's/8c72adab/7c72adab/g' /boot/grub/grub.cfg
sudo update-grub
sudo grub-install /dev/sda --modules=btrfs

Once done, I attach the disk to another machine and adjust both UUIDs:

sudo cryptsetup luksUUID /dev/sda1 --uuid "101b349b-2a70-4408-bae2-107d035c96e9"
sudo btrfstune -U 7c72adab-63cf-4526-b77e-78f11d2585e2 /dev/mapper/sda1-crypt

When I try to boot from the resulting disk I see:

error: no such cryptodisk found.
error: disk 'cryptouuid/001b349b2a704408bae2107d035c96e9' not found.
Entering rescue mode...
grub rescue> _

That said, *somewhere* the old LUKS UUID is still sitting. I expected it to be overwritten with the new one when I ran grub-install, but it didn't happen. Why is grub still trying the old UUID? What am I missing to make it try the new one? UPDATE: It appears that when grub-install is run, it possibly takes the old UUID from the currently mounted LUKS device (as opposed to from any config file) because I can't see where else the old UUID could come from. Is this what happens? Is there any way to override this behavior?