Hi,
I am using a 2014 Mac Mini with Ubuntu 20.04 (default install) on a USB connection (1 TB SSD)
This has been working fine for approx a week. Just when I am ready to consider a backup of the drive it somehow will not boot up.
Actually previously the Mac would boot into a small OSX drive - pressing the Mac alt button (on start up) allows one to boot into other drives. This has been working fine and then became erratic.
I booted from a USB boot stick and used gparted which reflects /dev/sdb1 and /dev/sdb3 as filesystem unknown.
Using a small spare drive I installed Ubuntu again and it erratically worked until I re-installed it again with the following partitions using gdisk
/dev/sb1 as EFI +512M
/dev/sdb2 as fs_boot +512M
/dev/sdb3 as fs_root (the rest of the drive)
new install Ubuntu with other (manual partitions) and formatting sdb1 as EFI, sdb2 as /boot and sdb3 as /root.
Once installed and rebooted then went
Code:
cd /boot/efi/EFI/ubuntu
and executed
Code:
mv shimx64.efi shimx64.efi_old
and
Code:
cp grubx64.efi shimx64.efi
; then reboot and all the strange messages such as "Failed to set Mok........" at bootup.
This seems quite robust and consistently boots up directly or using the Mac alt key choices. Point is it works properly and no problems.
HOWEVER, I have the problem with my 1TB drive:
Booting up from the small drive gparted still states the partitions are unknown.
I use gdisk
Code:
sudo gdisk -l /dev/sdb
GPT fdisk (gdisk) version 1.0.5
Partition table scan:
MBR: hybrid
BSD: not present
APM: not present
GPT: present
Found valid GPT with hybrid MBR; using GPT.
Disk /dev/sdb: 2000409264 sectors, 953.9 GiB
Model: Name
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): A0D13BCD-15E6-4EA3-A70F-554583C1CC7D
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 2000409230
Partitions will be aligned on 2048-sector boundaries
Total free space is 2669 sectors (1.3 MiB)
Number Start (sector) End (sector) Size Code Name
1 2048 1050623 512.0 MiB EF00 EFI System Partition
2 1050624 2000408575 953.4 GiB
it seems fine but if I use
Code:
sudo gdisk /dev/sdb1
[sudo] password for xxxxx:
GPT fdisk (gdisk) version 1.0.5
Partition table scan:
MBR: hybrid
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!
***************************************************************
Warning! Secondary partition table overlaps the last partition by
1999360033 blocks!
You will need to delete this partition or resize it in another utility.
and
Code:
Command (? for help): p
Disk /dev/sdb1: 1048576 sectors, 512.0 MiB
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): CD527C6A-F72B-48BE-88F0-A7C45C98A77A
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 1048542
Partitions will be aligned on 2048-sector boundaries
Total free space is 1048509 sectors (512.0 MiB)
Number Start (sector) End (sector) Size Code Name
2 1050624 2000408575 953.4 GiB 8300 Linux filesystem
as can be seen it reports number 2 and not 1!
using option p results in -
Code:
Command (? for help): p
Disk /dev/sdb1: 1048576 sectors, 512.0 MiB
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): CD527C6A-F72B-48BE-88F0-A7C45C98A77A
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 1048542
Partitions will be aligned on 2048-sector boundaries
Total free space is 1048509 sectors (512.0 MiB)
Number Start (sector) End (sector) Size Code Name
2 1050624 2000408575 953.4 GiB 8300 Linux filesystem
still number 2 followed by v
Code:
Command (? for help): v
Problem: partition 2 is too big for the disk.
Warning! Secondary partition table overlaps the last partition by
1999360033 blocks!
You will need to delete this partition or resize it in another utility.
Identified 2 problems!
it is a mess and if I follow through with /dev/sdb2 then
Code:
sudo gdisk /dev/sdb2
GPT fdisk (gdisk) version 1.0.5
Partition table scan:
MBR: hybrid
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!
***************************************************************
Warning! Secondary partition table overlaps the last partition by
1050657 blocks!
You will need to delete this partition or resize it in another utility.
and selecting p results in:
Code:
Disk /dev/sdb2: 1999357952 sectors, 953.4 GiB
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): F35C490F-3BAC-40B6-A2F1-C42BB23B0EF5
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 1999357918
Partitions will be aligned on 2048-sector boundaries
Total free space is 1050590 sectors (513.0 MiB)
Number Start (sector) End (sector) Size Code Name
2 1050624 2000408575 953.4 GiB 8300 Linux filesystem
and selecting v results in -
Code:
Problem: partition 2 is too big for the disk.
Warning! Secondary partition table overlaps the last partition by
1050657 blocks!
You will need to delete this partition or resize it in another utility.
Identified 2 problems!
As such I cannot afford to lose the sdb2 partition; although it is 900GB it is only using approx 200GB and I planned to shrisk the partition and the dd it over to a spare drive. It is the only copy now and I cannot recreate it.
My question is what are my options?
- can I use gparted and delete the sdb1 partition and recreate it? If so how do I do that as gparted does not seem to set all the correct flags (yes I have latest updates and still cannot do so)
- Should I use boot-repair? From my trials in the sm I got it to work after installing Ubuntu in default install (thus only having a EFI and root partition) - I found this quite unreliable but I could get it to boot up. Later, I shrunk the root partion and added aan additiona 512M partition; then applied the boot-repair, rebooted and it is what I am working from. My concern is although I used a small disk in the trials I am unsure as to the imapct if any on the 1 TB /dev/sdb2 partition - I cannot afford to lose it
- Any other reliable options?
I have read Rod's articles on gdisk/etc. and many other posts from all over however there is a "Windows" flavour to them which is not my situation
Any views?
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