Problem with VMXNET Interfaces (No buffer space available)

[shawly]

Hi guys,

I have an issue with the Emby Plugin. When it synced with Kodi or when I use the DLNA service with Windows Media Player, my FreeNAS just looses the Network connection and these messages pop up on the screen:



This is exactly the same problem: https://bugs.pcbsd.org/issues/8463
And this: https://bugs.pcbsd.org/issues/10414

Seems like it's the vmxnet3 drivers that cause the problem, has anyone got a fix for this or do I really have to use the E1000 interfaces?

 

[jgreco]

Yeah, what's with your insinuation that the E1000 is a bad option? It's rock effin solid, it's high performance, and it has none of the stupid problems that crop up with vmxnet3.

Do you really have to use vmxnet3 interfaces?

 

[depasseg]

Are you using 10G NICs in your ESX host? If not, then I don't see the need to deal with the hassle of vmxnet3.

 

[jgreco]

Are you using 10G NICs in your ESX host? If not, then I don't see the need to deal with the hassle of vmxnet3.

Even if you do have 10G, E1000 isn't limited to 1Gbps. It just happens to present itself as a hardware interface modeled on a 1Gbps ethernet chipset, but is perfectly capable of several Gbps.

 

[depasseg]

True, but if his host doesn't have 10G, then either way he's limited to 1G.

 

[jgreco]

True, but if his host doesn't have 10G, then either way he's limited to 1G. :)

Only off-host. I never did understand the whole "E1000 sucks" thing that so many people seem to engage in. vmxnet3 is a pile of male bovine excrement. If you update your hypervisor (or migrate a VM between hypervisors), vmxnet3 might need to be updated or even downgraded. It's twitchy and bug-riddled, especially including the ridiculous buffer-full thing, and when you update between revisions of your OS, there can be problems as well because the driver isn't actually part of FreeBSD. On the flip side, I can vmotion an E1000 VM between an ESXi 4.1 and an ESXi 5.5 hypervisor and the only problem is that IP connectivity drops for about a second, plus it uniformly just Works with every version of FreeBSD from 6.* to 10.*.

I realize that in some scenarios vmxnet3 has the potential to offer higher performance, but the downsides of random networking failures makes that kind of a nonstarter for me.

 

[shawly]

Oh I never knew, I've often read the E1000 is "slow" so I imagined I won't get the maximum transferrate out of my 1GBit network.. Never really tested it
Well, then my problem is pretty much solved I'd say, thanks! :D

 

[jgreco]

Well, E1000 *is* "slow" in that it has slightly more overhead than vmxnet3, plus you'd think that a PV-styled driver would also be incredibly resilient, driver-wise, by this point.

I can see why people WANT to believe that vmxnet3 is better, but I'm tired of VM's that go randomly deaf once a year or so. There's no excuse for that. I'll take the more reliable technology any day.