[oS-en] I managed to bork booting on a laptop, twice.

28 Dec 2021

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On my old laptop (classic BIOS, not UEFI) I have a separate /boot 
partition, created 2009, say. It has become too small, 190 MB. So I had to 
enlarge it somehow... or wait, perhaps remove it. Yes, I decided it was no 
longer needed and that I could get rid of it. Apparently years ago the "/" 
partition was reiserfs and I migrated it to ext4.

The partition layout was this:

minas-tirith:~ # lsblk --output NAME,KNAME,RA,RM,RO,SIZE,TYPE,FSTYPE,LABEL,PARTLABEL,MOUNTPOINT,UUID,PARTUUID,WWN,MODEL,ALIGNMENT 
NAME   KNAME  RA RM RO   SIZE TYPE FSTYPE LABEL  PARTLABEL MOUNTPOINT UUID                                 PARTUUID                             WWN                MODEL     ALIGNMENT
sda    sda   128  0  0 489.1G disk                                                                                                              0x500a075117eea2e5 Crucial_C         0
├─sda1 sda1  128  0  0   199M part ntfs   SYSTEM                      B456B22956B1EC6C                     b4e583dd-01                          0x500a075117eea2e5                   0
├─sda2 sda2  128  0  0 158.7G part ntfs                               D89260D89260BD1E                     b4e583dd-02                          0x500a075117eea2e5                   0
├─sda3 sda3  128  0  0  12.5G part crypto                             f9ef602f-61ee-4a77-807b-12a92879e1eb b4e583dd-03                          0x500a075117eea2e5                   0
├─sda4 sda4  128  0  0     1K part                                                                         b4e583dd-04                          0x500a075117eea2e5                   0
├─sda5 sda5  128  0  0     6G part swap   Swap             [SWAP]     675034b5-72ee-4db7-b8a4-d3cb197f9aad b4e583dd-05                          0x500a075117eea2e5                   0
├─sda6 sda6  128  0  0 196.1M part ext2   Boot             /boot      5b08978a-8461-4ecd-8049-bca31bbad2e6 b4e583dd-06                          0x500a075117eea2e5                   0
├─sda7 sda7  128  0  0    30G part ext4   Root             /          7d8f7fc8-df18-474b-be96-e43862cf3289 b4e583dd-07                          0x500a075117eea2e5                   0
├─sda8 sda8  128  0  0 251.1G part reiser Home             /home      434bcaab-addc-4efe-abd9-eeee576793c7 b4e583dd-08                          0x500a075117eea2e5                   0
└─sda9 sda9  128  0  0     7G part ext4   Other            /other     c0863c21-5df9-4040-9ad8-1f3f8b99424e b4e583dd-09                          0x500a075117eea2e5                   0
sr0    sr0   512  1  0  1024M rom                                                                                                                                  hp_CDDVDW         0
minas-tirith:~ #

minas-tirith:~/bin # fdisk -l /dev/sda
Disk /dev/sda: 489.1 GiB, 525112713216 bytes, 1025610768 sectors
Disk model: Crucial_CT525MX3
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xb4e583dd

Device     Boot     Start       End   Sectors   Size Id Type
/dev/sda1  *         2048    409599    407552   199M  7 HPFS/NTFS/exFAT
/dev/sda2          409600 333279231 332869632 158.7G  7 HPFS/NTFS/exFAT
/dev/sda3       950562816 976771071  26208256  12.5G 83 Linux
/dev/sda4       333284490 950549984 617265495 294.3G  f W95 Ext'd (LBA)
/dev/sda5       333284553 345863384  12578832     6G 82 Linux swap / Solaris
/dev/sda6       345863448 346265009    401562 196.1M 83 Linux
/dev/sda7       346265073 409175549  62910477    30G 83 Linux
/dev/sda8       409175613 935850509 526674897 251.1G 83 Linux
/dev/sda9       935852032 950548479  14696448     7G 83 Linux

Partition table entries are not in disk order.
minas-tirith:~/bin #

The MBR is "Syslinux ALTMBR", hardpointing to partition numer 4, the extended.

The boot record there would load grub residing in /dev/sda6 which would load the kernel, and done.

Ok, so I moved /boot partition over to /old.boot, and copied files over to 
/boot directory. Called YaST boot loader module, changed timeout to force 
it writing, and rebooted.

Text grub, loading initrd, and hang.

I then used an external rescue disk to mount sda7, chroot, run mkinitrd, 
run "grub2-mkconfig -o /boot/grub2/grub.cfg", run YaST boot loader module 
again...

After a few attempts, the rescue disk no longer boots on its own 
(big text black display with cursor blinking on top left corner, instead 
of grub menu), and the internal disk boots in text mode grub, but it 
boots (and has an entry for the external hard disk, which also works that 
way).

So, I have now two boot systems to repair (same computer, internal disk and
external via USB2).

   [correction: external disk is booting now]

Both are running Leap 15.2: I had to eliminate the /boot too small 
problem before attempting to upgrade to 15.3. Today, I had planned.

I need more eyes...

bootinfoscript says:

                   Boot Info Script 0.76      [13 April 2017]

Last git commit:       Also search for grub2 custom.cfg on FAT
Commit date:           2017-04-23T05:49:05Z

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

  => Syslinux ALTMBR (4.06 and higher) with boot partition 0x04 is installed in
     the MBR of /dev/sda.                                                   --> internal disk
  => Syslinux GPTMBR (4.04-5.01) is installed in the MBR of /dev/sdb.       --> external disk

sda1: __________________________________________________________________________

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

sda2: __________________________________________________________________________

     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:        /bootmgr /boot/BCD /Windows/System32/winload.exe

sda3: __________________________________________________________________________

     File system:       crypto_LUKS
     Boot sector type:  Unknown
     Boot sector info:

sda4: __________________________________________________________________________

     File system:       Extended Partition
     Boot sector type:  Grub2 (v1.99-2.00)
     Boot sector info:  Grub2 (v2.00) is installed in the boot sector of sda4
                        and looks at sector 396060737 of the same hard drive
                        for core.img. core.img is at this location and looks
                        for (,msdos7)/boot/grub2. It also embeds following
                        components:

                        modules
                        -------------------------------------------------------
                        fshelp ext2 part_msdos biosdisk
                        -------------------------------------------------------

- -->                Question: (,msdos7) is /dev/sda7? I'm confused now. It should be sda7 to be correct. If it points to sda6, it is not correct, old boot partition.

sda5: __________________________________________________________________________

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

sda6: __________________________________________________________________________

     File system:       ext2
     Boot sector type:  -
     Boot sector info:
     Operating System:
     Boot files:        /grub2/grub.cfg /boot/grub2/grub.cfg /grub2/custom.cfg
                        /boot/grub2/custom.cfg /grub2/i386-pc/core.img
                        /boot/grub2/i386-pc/core.img

- -->  this partition is now mounted at /old.and.separate.boot, not /boot. 
But I have not erased content yet.

sda7: __________________________________________________________________________

     File system:       ext4
     Boot sector type:  -
     Boot sector info:
     Operating System:  openSUSE Leap 15.2
     Boot files:        /boot/grub2/grub.cfg /boot/grub2/custom.cfg /etc/fstab
                        /boot/grub2/i386-pc/core.img

sda8: __________________________________________________________________________

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

sda9: __________________________________________________________________________

     File system:       ext4
     Boot sector type:  Grub2 (v1.99-2.00)
     Boot sector info:  Grub2 (v2.00) is installed in the boot sector of sda9
                        and looks at sector 945088400 of the same hard drive
                        for core.img. core.img is at this location and looks
                        for (,msdos9)/boot/grub2. It also embeds following
                        components:

                        modules
                        -------------------------------------------------------
                        fshelp ext2 part_msdos biosdisk
                        -------------------------------------------------------
     Operating System:  openSUSE Leap 15.0 Beta
     Boot files:        /boot/grub2/grub.cfg /etc/fstab
                        /boot/grub2/i386-pc/core.img

sdb1: __________________________________________________________________________

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

sdb2: __________________________________________________________________________

     File system:       ext4
     Boot sector type:  Grub2 (v1.99-2.00)
     Boot sector info:  Grub2 (v2.00) is installed in the boot sector of sdb2
                        and looks at sector 9141768 of the same hard drive for
                        core.img. core.img is at this location and looks for
                        (,gpt2)/boot/grub2. It also embeds following
                        components:

                        modules
                        -------------------------------------------------------
                        fshelp ext2 part_gpt biosdisk
                        -------------------------------------------------------
     Operating System:  openSUSE Leap 15.2
     Boot files:        /boot/grub2/grub.cfg /etc/fstab
                        /boot/grub2/i386-pc/core.img

sdb3: __________________________________________________________________________

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

sdb4: __________________________________________________________________________

     File system:       crypto_LUKS
     Boot sector type:  Unknown
     Boot sector info:

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

....

The rest, here:

<https://paste.opensuse.org/97794560>

Correction!

The external hard disk is now booting correctly. I did nothing to it, just 
power it off and on, remove and insert USB cable again.

I did run YaST module on the internal hard disk once more, prior to 
obtaining data.

The internal hard disk still produces a grub menu in text mode.

- -- 
Cheers

 	Carlos E. R.
 	(from 15.2 x86_64 at Telcontar)
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