2023 Update: Recent versions of REHL have completely disabled DES which can cause issues even when using the +ssh-rsa or +ssh-rsa. You can use the following command to enable SHA1, however, upgrading the server would be recommended.
update-crypto-policies --set DEFAULT:SHA1
Reason for it not working is some of the older weaker SSH encryption algorithms have been disabled. You can allow ssh to use it by specifying the following option.
From the above we see that the drive we just pluGged into the system is “sda” so our path and partition is “/dev/sda1”
The following command will run hashcat against “/dev/sda1”, change if the encrypted partition is different. Mode is to brute force every 8 numeric character combination. Refer to the following link to learn more about mask attacks. https://hashcat.net/wiki/doku.php?id=mask_attack
Note: You should be able to dump the header and work off of that as well.
sudo hashcat -a 3 -m 14600 /dev/sda1 ?d?d?d?d?d?d?d?d