ubuntu@ubuntu:~$ grep -i sda6 /var/log/syslog
Jun 25 01:42:08 ubuntu lvm[1097]:   /dev/sda6: read failed after 0 of 4096 at 220201943040: Input/output error
Jun 25 01:42:08 ubuntu lvm[1097]:   /dev/sda6: read failed after 0 of 4096 at 220202000384: Input/output error
Jun 25 01:42:08 ubuntu lvm[1097]:   /dev/sda6: read failed after 0 of 4096 at 0: Input/output error
Jun 25 01:42:08 ubuntu lvm[1097]:   /dev/sda6: read failed after 0 of 4096 at 4096: Input/output error
Jun 25 01:42:08 ubuntu kernel: [    7.481627]  sda: sda1 sda2 sda3 sda4 sda5 sda6 sda7 sda8
Jun 25 01:42:08 ubuntu kernel: [   10.124131] EXT4-fs (sda6): INFO: recovery required on readonly filesystem
Jun 25 01:42:08 ubuntu kernel: [   10.124133] EXT4-fs (sda6): write access will be enabled during recovery
Jun 25 01:42:08 ubuntu kernel: [  147.204149] EXT4-fs (sda6): error loading journal
Jun 25 01:42:10 ubuntu kernel: [  158.444325] Buffer I/O error on dev sda6, logical block 53760240, async page read
Jun 25 01:42:39 ubuntu kernel: [  186.822855] Buffer I/O error on dev sda6, logical block 53760240, async page read

fsck from util-linux 2.31.1
e2fsck 1.44.1 (24-Mar-2018)
fsck.ext2: Input/output error while trying to open /dev/sda6

The superblock could not be read or does not describe a valid ext2/ext3/ext4
filesystem.  If the device is valid and it really contains an ext2/ext3/ext4
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
    e2fsck -b 8193 <device>
 or
    e2fsck -b 32768 <device>