Horrible CIFS performance

[cyberjock]

Just an FYI.. your zfs get all looks fine. But your horrid iperf definitely shows that something is up with your network hardware.

 

[Lukas]

Just an FYI.. your zfs get all looks fine. But your horrid iperf definitely shows that something is up with your network hardware.

But could that something be so bad that it causes such incredibly bad speeds over SMB? I wouldn't be wondering if I were getting hundreds if Megabytes per second but 10 MB/s is like nothing!

 

[cyberjock]

hundreds of MB per second? Gb LAN at complete saturation will give you just 120MB/sec. You need to get a better understanding of what kinds of speeds to expect. And there's no way to determine where your limitation is when your iperf testing is as poorly as it is. Could be lost packets or something else that is wrong. Basically, you can't solidly point to a cause with iperf tests that are that poor. You are literally hitting your limit for raw data at just 35-40% of what you should be hitting.

 

[Lukas]

hundreds of MB per second? Gb LAN at complete saturation will give you just 120MB/sec. You need to get a better understanding of what kinds of speeds to expect. And there's no way to determine where your limitation is when your iperf testing is as poorly as it is. Could be lost packets or something else that is wrong. Basically, you can't solidly point to a cause with iperf tests that are that poor. You are literally hitting your limit for raw data at just 35-40% of what you should be hitting.

Please excuse my confusion, I'm carrying around a terrible cold and the head is a little heavy. Yeah, I've been mixing up Mbit/s and Mbyte/s.
I've now used another computer in my household to use iperf with the NAS and there got something around 700Mbit/s which admittedly looks much better. So, in this case my MacBook might have a network issue but that's not the topic right now ;)
With these results I think it might be safe to asume my server's hardware is working fine, right? But what now?

 

[cyberjock]

If you are getting 700Mbit/s that looks suspiciously like you are using a Realtek, which aren't recommend and have been well known to cause major random problems that make troubleshooting performance issues difficult. So I wouldn't say your hardware is "working fine". It's still suspect in my book. If you get good transfer rates from your household computer(I'd consider anything over about 50MB/sec to be good for your situation) then the problem is your crap Realtek. Otherwise you'll have to start narrowing down the limiting factor in your setup to find the cause.

 

[joeschmuck]

One thing I'd like to point out is the crappy NIC could be on either your FreeNAS machine or your computer. Also don't rule out a crappy network switch or a cable issue. We have seen cables cause poor performance too. If you can hook your NAS directly to your computer using a new cable then run your tests, that would be ideal. Even with a Realtek NIC you should be doing better but some Realtek NICs are better than others. The Realtek 8111 series seem to function better than some of the over series. And as you have heard, Intel are the better ones simply because they do the processing on the NIC vice offloading it to the CPU.