Using an external hard drive? Card not mounting?

I saw the note that using an external hard-drive isn’t supported

IMPORTANT Little Backup Box is designed to work with USB sticks as backup media. Theoretically, it’s possible to make Little Backup Box work with an external hard disk, but this setup is not officially supported.

I’m curious what it’d take to get this to work? And I’m wondering if what I’m seeing is related to not being officially supported.

I have an external hard drive and a SD memory card plugged into a powered USB hub, that’s then connected to a RPI 3B. Basically LBB will mount whatever device is listed under STORAGE_DEV, whether that’s the SD card or the HD, however it’ll refuse to mount CARD_DEV.

CONFIG:

STORAGE_DEV="sde1" # Name of the storage device
STORAGE_MOUNT_POINT="/media/storage" # Mount point of the storage device
CARD_DEV="sdb1" # Name of the storage card
CARD_MOUNT_POINT="/media/card" # Mount point of the storage card
SHUTD="5" # Minutes to wait before shutdown due to inactivity
SYNCTHING=false # Set to true to enable Syncthing
BAK_DIR="/home/pi/BACKUP" # Home directory path
DISP=false # Enable OLED display

Sys Info:

Devices

NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sdb           8:16   1 29.7G  0 disk 
└─sdb1        8:17   1 29.7G  0 part 
sde           8:64   0  1.8T  0 disk 
└─sde1        8:65   0  1.8T  0 part /media/storage
mmcblk0     179:0    0 29.8G  0 disk 
├─mmcblk0p1 179:1    0 41.8M  0 part /boot
└─mmcblk0p2 179:2    0 29.8G  0 part /

Disk space

Filesystem      Size  Used Avail Use% Mounted on
/dev/root        32G  3.3G   27G  11% /
devtmpfs        481M     0  481M   0% /dev
tmpfs           486M  234k  486M   1% /dev/shm
tmpfs           486M   13M  473M   3% /run
tmpfs           5.3M  4.1k  5.3M   1% /run/lock
tmpfs           486M     0  486M   0% /sys/fs/cgroup
/dev/mmcblk0p1   44M   24M   20M  55% /boot
/dev/sde1       2.0T   20G  2.0T   1% /media/storage
tmpfs            98M     0   98M   0% /run/user/999

If I reverse this by setting the SD card, sdb1, to STORAGE_DEV and the HD, sde1, under CARD_DEV, LBB will mount the SD card in /media/storage and ignore the HD.

So is this the reason for the IMPORTANT note about not supporting hard drive storage? Something else?

Thanks for your thoughts!

Best,
Josh

The reason for the notice is simple: adding a hard disk via a powered USB hub introduces a whole new level of complexity and makes the setup difficult to troubleshoot. Since I work on Little Backup Box in my spare time, I don’t have resources to support the external hard disk + USB hub scenario.

Kind regards,
Dmitri