Thank you all for offering to help. I don't think the drive powers down because it has worked consistently for over a year now and likely would have done this prior. The drive shows up accessible on another linux machine, but on an old win7 machine, the drive is 'there' but not showing under 'My Computer' to where I can run chkdisk.
Plugging the drive back on the Retronas debian system, the drive doesn't show as "8TB" like it does on the other Linux machine, but instead as the more generic "Seagate Expansion SW" which is not my naming. Could this be part of the problem?
I tried some things requested here: [NOTE: The two "serial redacted" other drives below are unmounted, unplugged Plex media drives to ignore]
root@retronas:/home/pi# sudo mount -av
/ : ignored
/boot : already mounted
/boot/efi : already mounted
none : ignored
/storage : already mounted
mount.nfs: timeout set for Tue Jun 11 17:03:59 2024
mount.nfs: Failed to resolve server /dev/disk/by-id/usb-Seagate_Expansion_Desk[serial redacted]-0: Name or service not known
mount.nfs: timeout set for Tue Jun 11 17:03:59 2024
mount.nfs: Failed to resolve server /dev/disk/by-id/usb-Seagate_Expansion_Desk[serial redacted]-0: Name or service not known
root@retronas:/home/pi#
Ran Checkdisk on Retronas/ Debian with the 'Disks' program:
"Filesystem intact: Filesystem ext4 on Seagate Expansion SW is undamaged."
Funny too is that when I press the 'play' button to mount it in disks it says it is now mounted and I can hit the square 'stop' button to unmount. Yet, if I go to the drive listed under 'Computer' and double click it, it has doublespeak:
"Unable to mount location - Can't mount file."
fstab info:
root@retronas:/home/pi# cat /etc/fstab
/etc/fstab: static file system information.
Use 'blkid' to print the universally unique identifier for a
device; this may be used with UUID= as a more robust way to name devices
that works even if disks are added and removed. See fstab(5).
systemd generates mount units based on this file, see systemd.mount(5).
Please run 'systemctl daemon-reload' after making changes here.
<file system> <mount point> <type> <options> <dump> <pass>
/dev/mapper/retronas--vg-root / ext4 errors=remount-ro 0 1
/boot was on /dev/mmcblk2p2 during installation
UUID=dd63f556-d137-45b2-97cb-7c442258f310 /boot ext2 defaults 0 2
/boot/efi was on /dev/mmcblk2p1 during installation
UUID=15E7-618A /boot/efi vfat umask=0077 0 1
/dev/mapper/retronas--vg-swap_1 none swap sw 0 0
UUID=21b5068f-3eb6-4ec9-8cab-027b673aba58 /storage auto defaults 0 0
/dev/disk/by-id/usb-Seagate_Expansion_Desk[serial redacted]-0:0-part2 /media/pi/MOVIES auto nosuid,nodev,nofail,x-gvfs-show 0 0
/dev/disk/by-id/usb-Seagate_Expansion_Desk[serial redacted]-0:0-part2 /media/pi/TV auto nosuid,nodev,nofail,x-gvfs-show 0 0
root@retronas:/home/pi#