USB Disk access


I have a RP3 with Volumio and an USB disk of 250GB.
It all plays well and fine, but I would like to access the disk thru the smb guest share (USB/NAS/Internal Storage) since it is more convenient to put files on the disk this way.
NAS and Internal Storage is open for guest access, but inside the USB there is a DISK folder where I have no access.
How should the disk be configured to be accessible from the guest smb share mount?

The access rights of /mnt/USB/DISK is

drwxr-xr-x 1 root root 131072 Jan 1 1970 DISK

sudo chmod a+w DISK

does absolutely nothing.

Presumably you need to set appropriate permissions for “DISK.”