Server is not booting after attempting to mount a disk

I was trying to mount a 10Tb disk on a ubuntu server. Due to the large size of the disk I had to use parted instead of fdisk. Unfortunately I did not enable GPT support in Linux kernel, prior to mounting the disk. Upon restarting the server, it does not boot up. My initial thought was, that it is a problem with grub, so I attempted to reinstall the grub2 on :

[*] /dev/sda [*] /dev/sdb 

Using the below commands:

apt-get install --reinstall grub-pc dpkg-reconfigure grub-pc 

But later on I fount it online that:

If you don’t add GPT support in Linux kernel, after rebooting the server, the file system will no longer be mountable, or the GPT table will get corrupted.

I am able to get access to the system using the rescue service offered by the host provider. Which is a linux system based on Debian. Below are the output of the df -h and fdisk -l commands that I get from the rescue Linux service:

#df -ha  Filesystem           Size  Used Avail Use% Mounted on proc                    0     0     0    - /proc sys                     0     0     0    - /sys udev                  32G     0   32G   0% /dev devpts                  0     0     0    - /dev/pts SERVER'S_IP_ADDRESS:/nfs  295G  124G  156G  45% /root/.oldroot/nfs overlay               32G  116K   32G   1% / securityfs              0     0     0    - /sys/kernel/security tmpfs                 32G     0   32G   0% /dev/shm devpts                  0     0     0    - /dev/pts tmpfs                 32G   13M   32G   1% /run tmpfs                5.0M     0  5.0M   0% /run/lock tmpfs                 32G     0   32G   0% /sys/fs/cgroup cgroup                  0     0     0    - /sys/fs/cgroup/systemd cgroup                  0     0     0    - /sys/fs/cgroup/cpu,cpuacct cgroup                  0     0     0    - /sys/fs/cgroup/cpuset cgroup                  0     0     0    - /sys/fs/cgroup/devices cgroup                  0     0     0    - /sys/fs/cgroup/memory cgroup                  0     0     0    - /sys/fs/cgroup/freezer cgroup                  0     0     0    - /sys/fs/cgroup/blkio cgroup                  0     0     0    - /sys/fs/cgroup/pids cgroup                  0     0     0    - /sys/fs/cgroup/perf_event systemd-1               0     0     0    - /proc/sys/fs/binfmt_misc hugetlbfs               0     0     0    - /dev/hugepages mqueue                  0     0     0    - /dev/mqueue tmpfs                6.3G     0  6.3G   0% /run/user/0     #fdisk -l Disk /dev/ram0: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram1: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram2: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram3: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram4: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram5: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram6: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram7: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram8: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram9: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram10: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram11: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram12: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram13: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram14: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/ram15: 64 MiB, 67108864 bytes, 131072 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   Disk /dev/loop0: 3 GiB, 3221225472 bytes, 6291456 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 /dev/sda: 477 GiB, 512110190592 bytes, 1000215216 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: 0x04cbff79  Device     Boot    Start        End   Sectors   Size Id Type /dev/sda1           2048   33556479  33554432    16G fd Linux raid autodetect /dev/sda2       33556480   34605055   1048576   512M fd Linux raid autodetect /dev/sda3       34605056 1000213167 965608112 460.4G fd Linux raid autodetect   Disk /dev/sdc: 9.1 TiB, 10000831348736 bytes, 19532873728 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   Disk /dev/sdb: 477 GiB, 512110190592 bytes, 1000215216 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: 0x4686096e  Device     Boot    Start        End   Sectors   Size Id Type /dev/sdb1           2048   33556479  33554432    16G fd Linux raid autodetect /dev/sdb2       33556480   34605055   1048576   512M fd Linux raid autodetect /dev/sdb3       34605056 1000213167 965608112 460.4G fd Linux raid autodetect   Disk /dev/md0: 16 GiB, 17163091968 bytes, 33521664 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   Disk /dev/md1: 511.4 MiB, 536281088 bytes, 1047424 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   Disk /dev/md2: 460.3 GiB, 494257111040 bytes, 965345920 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 

How can I address this issue?

Server: ubuntu-16.04.6-server

Provider: Hetzner