Unloading and Re-loading VirtuCache Driver
If for some reason VirtuCache driver needs to be unloaded and then loaded back in the ESXi kernel, please run the below two commands.
Command to unload the driver.
Ideally the unloading of the driver should be done during maintenance mode since it stuns storage I/O during the unload process. And if there is high storage IO passing through the host kernel, this stun might happen for 15-20 seconds.
You might see errors like watchdog-vnx2.PID does not exist; or unable to terminate watchdog-vnx2; can’t remove vnxcli; can’t remove vnxd.conf; can’t remove vnx2; etc. Ignore these errors, the command does unload the VirtuCache driver.
Loading the VirtuCache driver using the below command doesn’t require maintenance mode since storage IO is not stunned/disrupted.
Once VirtuCache driver is loaded, starting, stopping, pausing, assigning SSD/RAM to VirtuCache or assigning caching policy to VMs or Datastores doesn’t require maintenance mode. All these operations can be done live.