system initialization with error: ata2: COMRESET failed (errno=-16)

[emil]

Does the system halt (fail to complete boot) when you get these messages ?

Can you boot off another media to try to work out what ata2 might be referring to and run some disk checks ?
Try installing LL 5.8 perhaps ?

No problem with the system, it boots up "normally.

I can check the disk with the command "fsck". But the tutorial say "unmount the drive you want to check". Can you tell me how can I found that?

Terminal:
 mfm  ~  sudo lsblk
[sudo] password for mfm:
NAME  MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sda      8:0    0  1,8T  0 disk
├─sda1  8:1    0  200M  0 part
└─sda2  8:2    0  1,8T  0 part
sdb      8:16  0 298,1G  0 disk
├─sdb1  8:17  0  512M  0 part
├─sdb2  8:18  0  513M  0 part /boot/efi
├─sdb3  8:19  0    1K  0 part
└─sdb5  8:21  0 297,1G  0 part /