i just did a fresh install of ubuntu 20.04 on my ssd. i have a HDD that i want to use for storage but it's not being recognized.
i tried to mount it accorrding to [How do I access other drives?](https://askubuntu.com/questions/920992/how-do-i-access-other-drives) but it didn't work.
any ideas on what's going wrong here?
the strange thing is that `mount` works on `sdb5` and `sdb6` but not on `sdb7`. if at all possible i'd like to avoid formatting my HDD.

```
amir@amir-Lenovo:~$ sudo lsblk -o model,name,size,fstype,label,mountpoint
[sudo] password for amir: 
MODEL            NAME     SIZE FSTYPE  LABEL    MOUNTPOINT
                 loop0     62M squashf          /snap/core20/1587
                 loop1      4K squashf          /snap/bare/5
                 loop2  163.3M squashf          /snap/firefox/1635
                 loop3  400.8M squashf          /snap/gnome-3-38-2004/112
                 loop4   91.7M squashf          /snap/gtk-common-themes/1535
                 loop5   45.9M squashf          /snap/snap-store/582
                 loop6     47M squashf          /snap/snapd/16292
                 loop7    284K squashf          /snap/snapd-desktop-integration/
ADATA SU650      sda    447.1G                  
                 ├─sda1   7.6G swap             [SWAP]
                 ├─sda2  23.3G ext4             /
                 ├─sda3 401.3G ext4             /home
                 ├─sda4   488M ext4             /boot
                 ├─sda5   8.4G ext4             /var
                 ├─sda6     6G ext4             /tmp
                 └─sda7     7M                  
ST2000LM007-1R81 sdb      1.8T                  
                 ├─sdb1   450M ntfs    Recovery 
                 ├─sdb2   100M vfat             /boot/efi
                 ├─sdb3     1M                  
                 ├─sdb4    15M                  
                 ├─sdb5 291.6G ntfs             /media/amir/8210114210113E9B
                 ├─sdb6   841M ntfs             
                 └─sdb7   1.5T                  
amir@amir-Lenovo:~$ mount /dev/sdb6 /mnt/2TB
mount: /mnt/2TB: must be superuser to use mount.
amir@amir-Lenovo:~$ sudo mount /dev/sdb6 /mnt/2TB
amir@amir-Lenovo:~$ sudo mount /dev/sdb7 /mnt/HDD/
mount: /mnt/HDD: wrong fs type, bad option, bad superblock on /dev/sdb7, missing codepage or helper program, or other error.

```