NAS - QNAP - Configuration Files used - /etc/external_vol.conf

This is where external USB disks are defined.

cat /etc/external_vol.conf

returns:

[DEV_MAPPING_TABLE]
Bitmap = 0x2
2162691 = 1
 
[USB_Global]
Bitmap = 0x3e
ext_2162691_1_bitmap = 1
ext_2162691_2_bitmap = 2
ext_2162691_3_bitmap = 3
ext_2162691_5_bitmap = 4
ext_2162691_6_bitmap = 5
 
[Global]
volid_4_bitmap = USB_1
share_Dev1Partition1_bitmap = USB_1
volid_5_bitmap = USB_2
share_Dev1Partition2_bitmap = USB_2
volid_6_bitmap = USB_3
share_Dev1Partition3_bitmap = USB_3
volid_7_bitmap = USB_4
share_Dev1Partition5_bitmap = USB_4
volid_8_bitmap = USB_5
share_Dev1Partition6_bitmap = USB_5
 
[USB_1]
extId = 1
protocal = 2
devId = 2162691
partNo = 1
volId = 4
share_name = Dev1Partition1
wwn = D067E516480EF480F618623A
share_label = Dev1Partition1
 
[USB_2]
extId = 2
protocal = 2
devId = 2162691
partNo = 2
volId = 5
share_name = Dev1Partition2
wwn = D067E516480EF480F618623A
share_label = Dev1Partition2
 
[USB_3]
extId = 3
protocal = 2
devId = 2162691
partNo = 3
volId = 6
share_name = Dev1Partition3
wwn = D067E516480EF480F618623A
share_label = Dev1Partition3
 
[USB_4]
extId = 4
protocal = 2
devId = 2162691
partNo = 5
volId = 7
share_name = Dev1Partition5
wwn = D067E516480EF480F618623A
share_label = Dev1Partition5
 
[USB_5]
extId = 5
protocal = 2
devId = 2162691
partNo = 6
volId = 8
share_name = Dev1Partition6
wwn = D067E516480EF480F618623A
share_label = Dev1Partition6

NOTE: The NAS has the following USB ports:

4 built-in.
2 added through a PCI card.