- This topic has 9 replies, 6 voices, and was last updated May 24, 2021 by Joseph L.
VMXNET3 DirectPath I/O Enabled
Jim CMay 14, 2020 04:48:22 PM
We have ESXi 6.5 in our environment. We’re looking at turning off DirectPath I/O for any VMXNET3 adapters. The VRA’s have it enabled. Is that by design? It is a ‘bug’ and turns on by default so we manually turn it off on our VM’s that we create.Contara TMay 14, 2020 09:30:11 PM
Contara from Zerto Support.
The VRA is deployed with a VMXNET3 adapter, which is a 10 Gbps vNIC. A VRA cannot utilize multiple vNICs to improve throughput. This means that a single VRA is bound to 10 Gbps, or 1,250 MBps as a theoretical maximum.
Thank you.Paul GJanuary 22, 2021 01:43:42 PM
Being that the VRA is limited to one vNIC, it seems DirectPath I/O is turned on by design to provide better performance? Looking for clarification. Thanks!Kalsang DJanuary 28, 2021 09:05:57 PM
This is Kalsang from Zerto support.
Yes, DirectPath I/O is turned on by design to provide better performance.
Best regards,Joseph HMay 18, 2021 03:01:08 AM
What if we’re utilizing Nutanix clusters with ESXi hypervisor? From what Nutanix keeps telling me. Due to the storage locality, the Direct Path I/O option is recommended to be disabled on all VMware virtual machines.
Would we still keep it enabled for just the Zerto VRA VM’s?
I understand the use case for Direct Path if running a tiered architecture like a Flex-Pod or something. Considering vxRail and Nutanix hyper-converged designs, is this still the case?Joseph LMay 19, 2021 03:58:53 PM
I am Joseph with Zerto. I am investigating your inquiry and will provide a status soon.
JoeJoseph HMay 19, 2021 07:03:40 PM
Hello Joe, thank you! Our Nutanix reps had let us know that Nutanix technology doesn’t utilize the DirectPath I/O option, though in some situations, depending on the application it could be a different scenario.
For the most part, DirectPath I/O doesnt support vmotion, Fault Tolerance, HA or snapshots. Though, I also know the Zerto virtual appliances do not really use any of those functions.
Thank you in advance for your time and efforts.
-JosephJoseph LMay 19, 2021 09:57:23 PM
I have a request out to our product team. Once I receive an update I will post a response.
JoeJoseph LMay 21, 2021 04:51:37 PM
I continue to follow up with our product team regarding this inquiry. I will provide an update when available.
JoeJoseph LMay 24, 2021 10:01:28 AM
I received feedback from our product team. Regarding the VRA and Direct Path I/O, there is no impact on the VRA itself and it can be turned off for the VRA. I hope this was helpful. Thank you.