Post upgrade from ESXi 6.0 U3 to ESXI 6.5 U2, Sentinel HL USB licensing dongles were no longer visable to the guest VM nor within vSphere Web Client.
In ESXi 6.5, the legacy USB drivers, including xhci, ehci-hcd, usb-uhci, usb, usb-storage, and so on, are replaced with a single USB driver named vmkusb. The vmkusb driver is loaded by default and it is applied to all the USB Host Controllers (XHCI/EHCI/UHCI/OHCI), USB Keyboard, Mass Storage, and supported USB NIC devices connected to the host. This driver does have some compatibility and stability issues when compared to the legacy drivers.
Perform the following steps on each host in the cluster:
- Place the host in Maintenance Mode
- Enable SSH
- Connect via SSH and login as root.
- Enter the following command: esxcli system module set -m=vmkusb -e=FALSE
- Reboot the host
- Exit from Maintenance Mode
Rinse and repeat on each host. Technically you only need to perform these steps on hosts with USB devices connected but as a best practice, I always recommend having identical configurations on all hosts within a cluster.