I'm running kubuntu 16.04. I messed up UEFI (long ago), so it boots without it, but my Windows 10 partition won't boot. I don't care about that at the moment.

root is 30GB on sda4 home is 50GB on sda5.

All that works fine.

I copied root to root2 and home to home2 using rsync. I want to use these new partitions to experiment with upgrading kubuntu while leaving my main system intact.

Later, I want to make another copy of root and home just for backup (in other partitions I have set aside) and I will want that to be bootable as well.

root2 is 30GB on sda6 and home2 is 50GB on sda7.

I modified /etc/fstab on root2 to reflect the new partition LABELs.

When I try to boot using root2 (from my grub menu), I get into an ash shell from busybox and have to reboot to get out of it, so I did something wrong in grub or Linux and it looks like it can't find where or what to boot.

It displays some sort of traceback, but I don't understand it and I don't see it complaining about anything.

I asked almost the same question a few years ago, but never figured it out.

It was suggested in that question that I needed to chroot into the new root partition and run update-grub because I don't have a separate boot partition. I gave that a quick try and found that I don't know how to do that successfully.

What steps should I take to resolve this?

Details:

Root entry in grub (displayed by grub-customizer)

(This is the part that works as is.)

recordfail
load_video
gfxmode $linux_gfx_mode
insmod gzio
if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
insmod part_gpt
insmod ext2
set root='hd0,gpt4'
if [ x$feature_platform_search_hint = xy ]; then
 search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt4 --hint-efi=hd0,gpt4 --hint-baremetal=ahci0,gpt4 a184c235-bbb7-4e0b-86ab-ab8f5d4a2941
else
 search --no-floppy --fs-uuid --set=root a184c235-bbb7-4e0b-86ab-ab8f5d4a2941
fi
 linux /boot/vmlinuz-4.4.0-112-generic root=UUID=a184c235-bbb7-4e0b-86ab-ab8f5d4a2941 ro quiet splash $vt_handoff
initrd /boot/initrd.img-4.4.0-112-generic

/etc/fstab

bigbird@sananda:/etc$ cat fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
# / was on /dev/sda4 during installation
##UUID=a184c235-bbb7-4e0b-86ab-ab8f5d4a2941 / ext4 errors=remount-ro 0 1
# /home was on /dev/sda5 during installation
##UUID=c81a6925-0631-484c-88d5-245e2e042652 /home ext4 defaults 0 2
# swap was on /dev/sda10 during installation
##UUID=3ef9528c-1927-40fd-8729-33506d440101 none swap sw 0 0
## automount dataspace - JJP
##UUID=eb1774a1-2a44-4f03-8562-26b6339170f0 /media/dataspace ext4 auto,rw,suid,exec,async,atime 0 1

LABEL=root / ext4 errors=remount-ro 0 1
# /home was on /dev/sda5 during installation
LABEL=home /home ext4 defaults 0 2
# swap was on /dev/sda10 during installation
UUID=3ef9528c-1927-40fd-8729-33506d440101 none swap sw 0 0
## automount dataspace - JJP
LABEL=dataspace /media/dataspace ext4 auto,rw,suid,exec,async,atime 0 1

New stuff:

(I did a kernel update in root after I copied it to root2. That's why the versions here are slightly older.
Once it boots, I'll fix that.)

insmod part_gpt
insmod ext2
set root='hd0,gpt6'
if [ x$feature_platform_search_hint = xy ]; then
 search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt6 --hint-efi=hd0,gpt6 --hint-baremetal=ahci0,gpt6 caf3cb64-a51a-4298-bf34-5f97fa3b1308
else
 search --no-floppy --fs-uuid --set=root caf3cb64-a51a-4298-bf34-5f97fa3b1308
fi
linux /boot/vmlinuz-4.4.0-104-generic root=UUID=caf3cb64-a51a-4298-bf34-5f97fa3b1308 ro quiet splash $vt_handoff
initrd /boot/initrd.img-4.4.0-104-generic

/etc/fstab (on sda6)

bigbird@sananda:/media/work/etc$ cat fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
# / on /dev/sda6
##UUID=caf3cb64-a51a-4298-bf34-5f97fa3b1308 / ext4 errors=remount-ro 0 1
# /home on /dev/sda7
##UUID=a75b6be1-5336-4eaf-92db-da1393b3d412 /home ext4 defaults 0 2
# swap was on /dev/sda10 during installation
##UUID=3ef9528c-1927-40fd-8729-33506d440101 none swap sw 0 0
## automount dataspace - JJP
##UUID=eb1774a1-2a44-4f03-8562-26b6339170f0 /media/dataspace ext4 auto,rw,suid,exec,async,atime 0 1

LABEL=root2 / ext4 errors=remount-ro 0 1
# /home on /dev/sda7
LABEL=home2 /home ext4 defaults 0 2
# swap was on /dev/sda10 during installation
UUID=3ef9528c-1927-40fd-8729-33506d440101 none swap sw 0 0
## automount dataspace - JJP
LABEL=dataspace /media/dataspace ext4 auto,rw,suid,exec,async,atime 0 1
bigbird@sananda:/media/work/etc$

bigbird@sananda:~/pq$ ls -l /dev/disk/by-label
total 0
lrwxrwxrwx 1 root root 11 Jan 11 21:43 dataspace -> ../../sda12
lrwxrwxrwx 1 root root 10 Jan 11 21:43 ESP -> ../../sda1
lrwxrwxrwx 1 root root 10 Jan 11 21:43 home -> ../../sda5
lrwxrwxrwx 1 root root 10 Jan 11 21:43 home2 -> ../../sda7
lrwxrwxrwx 1 root root 10 Jan 11 21:43 home_bak -> ../../sda9
lrwxrwxrwx 1 root root 10 Jan 11 21:43 root -> ../../sda4
lrwxrwxrwx 1 root root 10 Jan 11 21:43 root2 -> ../../sda6
lrwxrwxrwx 1 root root 10 Jan 11 21:43 root_bak -> ../../sda8
lrwxrwxrwx 1 root root 11 Jan 11 21:43 winbak -> ../../sda11
lrwxrwxrwx 1 root root 10 Jan 11 21:43 Windows10 -> ../../sda3
bigbird@sananda:~/pq$

bigbird@sananda:~/pq$ ls -l /dev/disk/by-uuid
total 0
lrwxrwxrwx 1 root root 11 Jan 11 21:23 3ef9528c-1927-40fd-8729-33506d440101 -> ../../sda10
lrwxrwxrwx 1 root root 10 Jan 11 21:23 4630B96A30B9619B -> ../../sda3
lrwxrwxrwx 1 root root 10 Jan 11 21:23 52B7-E591 -> ../../sda1
lrwxrwxrwx 1 root root 11 Jan 11 21:23 7E8C3007301FA4AD -> ../../sda11
lrwxrwxrwx 1 root root 10 Jan 11 21:23 8f034ecf-5d98-4753-80d1-8099cf3bb641 -> ../../sda9
lrwxrwxrwx 1 root root 10 Jan 11 21:23 a184c235-bbb7-4e0b-86ab-ab8f5d4a2941 -> ../../sda4
lrwxrwxrwx 1 root root 10 Jan 11 21:23 a75b6be1-5336-4eaf-92db-da1393b3d412 -> ../../sda7
lrwxrwxrwx 1 root root 10 Jan 11 21:23 c81a6925-0631-484c-88d5-245e2e042652 -> ../../sda5
lrwxrwxrwx 1 root root 10 Jan 11 21:23 caf3cb64-a51a-4298-bf34-5f97fa3b1308 -> ../../sda6
lrwxrwxrwx 1 root root 10 Jan 11 21:23 cce6b9f2-1dcc-4a53-b15b-73c595c2f6f5 -> ../../sda8
lrwxrwxrwx 1 root root 11 Jan 11 21:23 eb1774a1-2a44-4f03-8562-26b6339170f0 -> ../../sda12

Modify /boot/grub/grub.cfg

You can modify the boot configuration file /boot/grub/grub.cfg manually (without getting into chroot). I have done it and I know that it works.

Modfify the file to match the references to the partitions (the UUIDs of the root partition) corresponding to what you did with /etc/fstab. I am not sure that you can use labels, so I suggest that you list the UUIDs with

sudo blkid

and use the values that you find for the second version of root partition.

Get a second drive of at least the same size

You may find it easier to get a second drive of at least the same size and clone from original drive to this second drive. 'Clone the whole drive'. Then you need not modify anything, but you should not boot the computer from any of these drives, when they are both connected.

Download a Clonezilla iso file, create a live drive (USB pendrive or DVD disk), boot from it and clone.

Afterwards you can use the second drive in an external box for backup purposes (using whatever backup method/tool that you want).

Rather than copying OS install it

I would install Kubuntu to sda6 rather than copying sda4 to sda6 and patching things here and there. The advantage is grub will automatically setup the triple boot for you.

After OS installation copy the package list and reinstall packages. There are a few Q&A's describing how to automate the process:

• https://unix.stackexchange.com/questions/190853/backup-and-restore-list-of-installed-packages-and-apt-sources


• https://www.ostechnix.com/create-list-installed-packages-install-later-list-centos-ubuntu/


• How can I backup my programs/applications, so that after I reinstall a new one, I can still use the backup-ed ones?

After automatic installation of packages then copy sda5 (/home) over top of sda7 (/home). If you did this before package installation some data / configurations files could be overwritten.

As far as UEFI being broken you could post that as a separate question.