One step you may have overlooked was checking man fstab - in other words, the system manual for creating & maintaining /etc/fstab. Even though it's a bit dated now (Feb 2015), and has at least one error (re behaviour of nofail), it does reflect the software on your system. I've always found the fstab incantations a bit arcane, and man fstab at least does a reasonable job of showing the syntax.
One of the problems I saw in your fstab entry was that the third field (fs_vfstype) is missing. man fstab tells us that there should be an entry in this field. It appears you have put the term auto in the third field. AFAIK, auto is not a proper entry for the type of file system. You should use instead the name of the file system used for formatting the drive/partition being mounted. For example: ext4, ext3, vfat, exfat, ntfs, etc, etc. The system manual man mount has additional details on the options.
Moving on to your 4th field entries (fs_mntops), you have the option string:
nofail,uid=1000,gid=1000,noatime
Perhaps you intended that your 3rd field entry auto was to be included here? It would have been a valid entry.
My recommendation for your 4th field (fs_mntops) entries is as follows:
rw,user,nofail
rw: allow read and write on the mounted filesystem
user: allow a user to mount the filesystem - which would include user pi (typically the same as uid=1000,gid=1000, but not necessarily)
nofail: don't stop the boot process if this filesystem cannot be mounted. Note that man fstab says do not report errors, but actually it halts the boot process on failure (last I checked anyway).
You do not need the noatime option as that is typically used only on devices such as SD cards which have a "wearout mechanism"
Finally, the two 0 (zero) values at the end of your /etc/fstab entry are the fifth and sixth fields. They are fine as is, but 0 is the default for both so they aren't actually needed in your case.
If you'll try this entry in /etc/fstab, I hope it will work. If not, let us know & we'll fix that:
UUID=c6c93d58-8648-4e33-9178-ca6c1d4043e3 /mnt/1TB-PiDrive ext4 rw,user,nofail 0 0
Please verify that your HDD is formatted as ext4 before trying this; otherwise replace ext4 with the format used.
Testing your /etc/fstab entries:
Finally, you can experiment with various options in your /etc/fstab entry without having to reboot:
- unmount the drive (if it's mounted):
sudo umount /mnt/1TB-PiDrive
- make a change to your
/etc/fstab entry; e.g.:
FROM: UUID=c6c93d58-8648-4e33-9178-ca6c1d4043e3 /mnt/1TB-PiDrive ext4 rw,user,nofail 0 0
TO: UUID=c6c93d58-8648-4e33-9178-ca6c1d4043e3 /mnt/1TB-PiDrive ext4 rw,user,nofail.
- have
mount re-read /etc/fstab to verify this works (it still mounts):
sudo mount -av
This will attempt to mount all (-a) drives in /etc/fstab and give a verbose (-v) report. For example, on one of my systems (without unmounting anything first):
sudo mount -av
/proc : already mounted
/boot : already mounted
/ : ignored
/home/pi/mntThumbDrv : already mounted
/home/pi/mntBackupDrv : already mounted
/home/pi/mntPassport : already mounted
/home/pi/mntNetgearNAS-3 : already mounted
