Comments on: Citrix XenServer Slow Network Performance

By: Trond Eirik Haavarstein

Trond Eirik Haavarstein — Tue, 15 Nov 2011 23:01:44 +0000

Hi Lee, I have not experienced this. Please try a iperf against physical and virtual host to see if there’s amy difference. cmd : iperf -c ipadr -f M -t 30 -i 1. Download iperf here : https://nocweboldcst.ucf.edu/files/iperf.exe

By: Lee

Lee — Tue, 15 Nov 2011 20:06:45 +0000

Eirik -

I have an issue where I have 915Blades connected through a 10GB network. Running benchmarks on my vm’s I noticed that my disk I/O is really bad. I get about 20MB/sec average. I have vm’s on EQLogic and NetApp and still get bad disk I/O. I’m wondering if implementing the Checksum Offload would help resolve my problem. Have you ever encountered what I’ve just written? Would like your feedback.

By: XenServer Performance and ScalabilityTesting « Roshan Ratnayake – Solution Architect

Tue, 01 Nov 2011 23:22:57 +0000

[...] http://www.xenappblog.com/2010/citrix-xenserver-slow-network-performance/ [...]

By: Trond Eirik Haavarstein

Trond Eirik Haavarstein — Thu, 20 Oct 2011 22:58:34 +0000

Glad I could help you solve this Scott

By: Scott

Scott — Thu, 20 Oct 2011 21:29:15 +0000

Eric,

Thank you so much for the assitance you provided in your email.

Once I was able to test and verify that my network was functiioning as expected, I was able to key in on one of your suggestions pertaining to the vCPU assignment. I had never read or came across anything mentioning this very important detail until you contacted me.

As I stated in my original posting, I had converted a Physical Xenapp server to a Virtual Machine (4) and other than removing the left-over drivers, in my mind the options that remained (memory config and CPU’s etc) should have provided a snappy workload that either met or exceeded the physical server’s performance. What I exerienced was less than stellar. But after scaling back the vCPU’s to 2 (from 4), all of my login issues were gone and they’ve been fine since. I was even able to scale back the memory consumption to save even more resources on my hosts. Truth be told, my Xenapp VM’s are snappier than my Physical Xenapp servers.

So thank you for your help and keep up the great work you’re doing here.

By: Scott

Scott — Thu, 29 Sep 2011 13:28:00 +0000

Trond, I’m sorry but I did not get your email. I’ve checked my AntiSpam system and didn’t see anything come in from you. You sent it to administrator@bathweg.com?

Thanks,

By: Trond Eirik Haavarstein

Trond Eirik Haavarstein — Wed, 28 Sep 2011 22:47:12 +0000

Hi Scott, please check the email I sent you

By: Scott

Scott — Tue, 27 Sep 2011 17:08:22 +0000

Hi,

Can you elaborate on the Network Slowness that this is meant to address? In my situation I have two XenServer hosts running v5.6.0-31188p with each running 2 P2V converted VM’s running XenApp 5. Both Hosts are connected to a SAN via a separate Gb LAN. For some reason when more than 2 users land on the same server at the same time (give or take a minute) it can take as long as 10 minutes for them to get logged in. But if a single user logs on it can be a fast as 35 seconds. However I don’t have this problem on my Physical XenApp servers.

Any thoughts would be appreciated.

By: Rodolfo

Rodolfo — Thu, 18 Aug 2011 02:47:55 +0000

Hello,

This post, save my life!!

By: Trond Eirik Haavarstein

Trond Eirik Haavarstein — Wed, 30 Mar 2011 15:37:18 +0000

Hi Thomas, probably depends on who you are talking to at Citrix. Anyway it have worked for me without reboot. Just keep in mind that you have to run this script every time you add a new VM, because the script is also setting this on the VIF adapter (Virtual).