I suggest you NOT mount the backup drive in fstab. What I settled on is mounting by drive label.
Here's what I do to prep a drive and give it a drive label.
######### Prep backup drives Note: this will wipe the drive.
Code:
gdisk /dev/sd?
d
n
defaults a few times
w
# format it to ext4
mkfs -t ext4 -q /dev/sd?1 -L backup_offsite
Now that the disk has a backup label and is formatted, you can mount like this:
# Mount it and make the backup directory
Code:
mount -L backup_offsite /mnt/backup_offsite
mkdir -p /mnt/backup_offsite/dump
Then put in /etc/crontab to mount at boot
Code:
@reboot root mount -L backup_offsite /mnt/backup_offsite
Note: the above command is a tad different than mine as I put this command in a script file that then runs from cron.
Then here's my relevant portion of storage.cfg
Later version of proxmox support is_mountpoint. This will stop proxmox from backing up if the drive is not mounted. Also, I disable proxmox creating the backup directory.
Edit /etc/pve/storage.cfg
Add to the bottom:
Code:
dir: backup_offsite
path /mnt/backup_offsite
content backup
maxfiles 3
shared 0
is_mountpoint 1
mkdir 0