Comment 12 for bug 1815588

I could swear I already tested this for 1. Redirecting USB while guest is running), but this time it worked. Thanks for the suggestion @paelzer

I unmounted both partitions and then redirected. Here's the journalctl output:

Oct 28 15:24:38 hostname udisksd[1229]: Cleaning up mount point /media/user/2TB-1Partition (device 8:2 is not mounted)
Oct 28 15:24:38 hostname ntfs-3g[31458]: Unmounting /dev/sda2 (2TB-1Partition)
Oct 28 15:24:38 hostname udisksd[1229]: Unmounted /dev/sda2 on behalf of uid 1000
Oct 28 15:24:43 hostname udisksd[1229]: Cleaning up mount point /media/user/LACIE SETUP (device 8:1 is not mounted)
Oct 28 15:24:43 hostname systemd[1]: Stopping Clean the /media/user/LACIE SETUP mount point...
Oct 28 15:24:43 hostname systemd[1]: Stopped Clean the /media/user/LACIE SETUP mount point.
Oct 28 15:24:43 hostname udisksd[1229]: Unmounted /dev/sda1 on behalf of uid 1000
Oct 28 15:25:03 hostname kernel: sd 0:0:0:0: [sda] Synchronizing SCSI cache
Oct 28 15:25:03 hostname kernel: sd 0:0:0:0: [sda] Synchronize Cache(10) failed: Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
Oct 28 15:25:03 hostname upowerd[1520]: unhandled action 'unbind' on /sys/devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4/1-3.4.2/1-3.4.2:1.0
Oct 28 15:25:03 hostname kernel: usb 1-3.4.2: reset high-speed USB device number 11 using xhci_hcd
Oct 28 15:25:03 hostname upowerd[1520]: unhandled action 'bind' on /sys/devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4/1-3.4.2/1-3.4.2:1.0
Oct 28 15:25:03 hostname upowerd[1520]: unhandled action 'unbind' on /sys/devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4/1-3.4.2/1-3.4.2:1.0
Oct 28 15:25:03 hostname upowerd[1520]: unhandled action 'bind' on /sys/devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4/1-3.4.2/1-3.4.2:1.0

If this is repeatable, then it solves my immediate problem. Perhaps they can also identify some usability improvement in the SW stack in the future.