Slow network speed (LAN and internet) on ESXI 5.1 VMs

[phuz]

I have a ML350 G5 running esxi 5.1. 

My LAN is 1 Gb / sec.

I have noticed that copying files to/from my NAS occurs at about 5-6MB/sec.  Similarly, if I run a speedtest from any of the VMs, I get a downstream of about 40Mb/sec while my connection is 180Mb/sec downstream.  Knowing that all the VMs share the single NIC, I shut them all down except one, but the transfer speeds do not increase.  This occurs on my Windows 7 VMs and XP VMs.  I tried changing the network adapter types, but for the most part, they are running VMXNET 2 or 3.

Any ideas why this is happening or what I should look for?

Thanks.

[mcrape]

That's odd. A few things you could check:

• Are you able to plug a physical win 7 host into the same switch and run a speed test?
• Are VMware Tools installed / up to date?
• Is this host under heavy CPU load?
• double check to make sure the portgroup isn't running in promiscuous mode - this would send a lot of unwarranted traffic to each host.

Do you have any other OS VMs running on there (e.g. Server 2012) that you can test from?

[phuz]

Yes, my other computers that are directly connected to the router (through a 1Gb switch) have no problem transferring at speeds you would expect.

VMware tools are up to date.  Host CPU load is minimal.  Promiscuous mode shows "Reject".

For a secondary test, I tried FTP'ing to my NAS and grabbed a ~700MB file.

Results:

ftp: 766623744 bytes received in 264.22Seconds 2901.47Kbytes/sec.

Yikes!!

[SpoonTuxedo]

How does the NAS connect to the network? Through the same switch?

Have you checked the port status on the switch for any errors? Look for port speed, duplex mismatch etc.

[phuz]

The NAS connects to the same Gigabit switch and operates fine.

The ML350 (ESXI) shows 1000Mb connection under networking in vSphere, so I don't know what the hangup is.

It is certainly behaving like a 100Mb connection.

I also have a VM-only network, and I tried transferring the same ~700MB file over that network.  (from a Win 7 VM to Win XP VM)  That took 60 seconds and it should have flew considering its not actually going out on the communication media.

[SpoonTuxedo]

If you plug a laptop into the the switch using the same cable, how is the traffic to the NAS?

I'm suspecting there's a physical connection issue, happy to be wrong but it's where I would start.

[phuz]

Good point.  I'll give that a shot tomorrow.  I'm currently in the middle of a 180GB download on that VM and it still has 3 hours remaining because it won't DL any faster than 6MB/sec.

[phuz]

OK I didn't feel like waiting.

Plugged in laptop to where the ESXI host was, and speeds are perfect.  Physical connection is not the issue.

[phuz]

A couple more tests today.  Fired up a 32-bit Windows 7 machine and copied the ~700MB file.  It transferred around 35MB/sec.  I am OK with that.  Internet speed test, though, would not exceed 70Mbit/sec.  Strange. 

I fired up the Windows XP VM and copied the same file.  It copied at less than 10MB/sec again.  It is a brand new VM using VMXNET 2.  Why on earth will this not transfer at the same speeds as the other VM?  CPU utilization showed about 40% during the transfer and network utilization showed 8%.  Clearly neither is being taxed to the max so I don't understand the bottleneck.

[mcrape]

Well this is really odd. Have you tried doing a test from VM to VM on the same host? If possible, could you do one from the same OS and another test from a different OS?

[phuz]

Results:

Win 7 <--> Win 7:  ~30MB/sec

Win 7 --> XP:  ~8MB/sec

XP --> Win 7: ~20MB/sec

Basically anything coming IN to the XP machine is slow.  Outgoing is still not as fast as it should be.  I tried a second XP VM that I have too, with the same results.

[TheProf]

I am wondering if it could be perhaps the drivers for uplinks... I've seen problems like these in the past due to NIC driver compatibility at the host level (not VM). I am also assuming you used the vendor ESXi image?

Take a look at this link and see if it might be helpful.

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=100408...

[phuz]

Actually, my buddy had this server left over from an old job and gave it to me.  I think he used the HP image for it.

At the end of the day, it's not a deal breaker because I am looking to upgrade this thing anyway (I have another thread about that), but in the short term, I was trying to figure this out.

[addision1]

This is an old thread but I had the same problem and wanted to give my solution as this thread pops up at the top of the search list. I had an HP ML350 gen9 installed with esxi 6.5 and installed with my first test machine server 2012.

I was getting horrible network performance. I found out that the server bios power settings were set for a low power mode. I tried many things before this, updating drives, using different network card settings and nothing would work.

Once I changed the power settings in bios everything worked fine!

Good luck!