So I was seeing this: -
cd /volumeUSB1/usbshare
touch foo
touch: foo: Permission denied
when I tried to write a file to an EXT2-formatted USB drive on my Synology DS414 NAS as a non-root user.
However, I was able to write a file as the root user.
Yes, the USB drive appears as this: -
/dev/sdr1 on /volumeUSB1/usbshare type ext3 (0)
and my admin user did NOT have Read/Write access to that drive.
It was actually this article that led me to the solution: -
so I will explore the SSH keys option :-)