TO begin, let me share an article that articulates what may of you have gone through to get to this point. Many of you started at lync 2010 and are now on Skype for Business. Are you using the same hardware? If so, your problems have come from the past to haunt you.
*Disclaimer: I use Lync and SFB and Skype for business, all to refer to the general term of Lync or Skype. I believe we are all moving to just Skype, but it would be nice if MS just rolled it all to just Skype! one word please!
This article is written for a customer I have in a nearby nation, to the United States. He has a well used Lync 2013 Deployment. He has also had a lot of trouble. From having calls fail on Fridays, to having the Web sites fail on Wednesday, every week, for several weeks in a row.
I had some time to look at this case from a distance, after being very close to the situation for several weeks in a row. As a series of chance activities, this customer ended up going to the VMware department, instead of Lync. This was a very good route! As it turns out, The VMware agent caught the Virtual Machine with 4GB of ram!.
What a coincidence! I had caught the same customer changing his resources myself! That was all it took. All the pieces were clear.
I need to express in no uncertain terms, how vigilant you must be if you decide to Virtualize Lync or Skype for Business! While there may be some issues with Lync and Hyper-V, I am being honest, when I say that most of the virtual issues have been with VMware. Now I know I may take flack for that statement. I am a Microsoft Support Agent, so I do have a bias. I don’t make that statement to support my own brand. I am a Lync Professional and I am telling you my honest experience over 7 years with Lync and Skype for Business.
With that said, let me break it down for you, as much as I can. Let me first bulletize what the supported Lync Server would look like on ESX:
Skype Server on ESX
- 1. The VHDX needs to be fully expanded, and should not be an remote disk- ISCSI disk.
- The Ram must not be dynamic, and must be a minimum of 24GB of ram. 32 or more is recommended.
- The processors must not have NUMA complications, and Hyper threading should be disabled. The ESX should only be presenting physical processors on a machine where SFB is installed.
- Networking is in flux. I think this is where some issues are still being resolved. Let me say that I recommend you use a dedicated physical nic to the VMware VM, which ever Nic type that is. VMXnet3 nics seem to have an issue, but please keep reading the documentation. Example and Example
- The Balloon Driver needs to be disabled completely.
- A Lync/SFB machine should not be moved, or migrated from host to host, even for maintenance.
- Vms should be left alone to run, and cannot stand having resources change at all. This is a real time application, and cannot be live migrated like many machine types can.
- Do not use snapshots on Vmware, as this will just cause an issue, if you ever tried to roll back. Just full back up, and restore if necessary.
- Do not install Antivirus or threat protection on Lync systems.
- Rely on the security provided by an Edge and reverse proxy server.
I suppose I could keep going. So there I said it! I don’t know if your getting the feeling that Lync should be on a physical machine? I have seen many VM lync deployments, and I wont go so far as to say that. I will say, If you choose SFB and you deploy to ESX, you must remain committed to the best practices. You cant even slip once. I guarantee you will see problem.
EDIT Due to Feedback from another Skype Fan
I was called out on the fact that I cannot maintain the Skype cannot be virtualized. In todays market, we must be able to function with any kind of Hypervisor. I do not disagree with that position. Believe me, I did not want to come off that way. So let me clarify, to say Virtualization is not the problem, so much as Resource control. I am not back tracking much. I am saying that your are not likely going to be free to just move a Lync server around, if you don’t want interruptions. The SDP protocol, is not built to be live migrated! My commenter below rightfully said that all three of the technologies I mentioned worked. I don’t disagree. The issue with real time voice, is in those parts of the day when things are busy, and you find you need to move resources around, or you have automation to move resources around. This not going to work with SKYPE! Skype needs dedicated resources, and you should not change them!
I hope it is clear what my intentions are!! I love VMware and I love Hyper-V. However, all of my problem environments are with VMWare. This is on Lync, not VMware! I can say simply that Skype is not very happy with resources that are changing dynamically. So now.. back to your article!
So before you go looking for where I am incorrect in these statements, Please start with the requirements for todays SFB server. Requirements for SFB server, are not small. and then, I don’t mind if you jump into the fire. Here let me supply some oxygen for you! Below find ways to enter the battle:
- Discussion on Lync Virtual Requirements
- Microsoft’s position
- I know Citrix does it right, but not relevant maybe
- Of course VMware will clear things up
I think that is enough to get you started. So no matter what you think about Lync, it all boils down to two things, Compute resources, and the network. If either of those is a fail, then your lync deployment is a fail. Microsoft puts it more eloquently:
“Lync Server is designed to consume the full capabilities of a physical server and will perform poorly if the required compute resources are not available when needed. To help the virtualization of Lync Server 2013 to be successful for your organization, follow the guidelines provided in this white paper”
My friends, you came to this sight, perhaps to find out what not to do with your Lync Server. Look at the statement above. My experience is if you have been having issues for month’s, then there is a 69% chance your answer is in the blue text above. My chances of being right are much lower if you deploy your Lync server like the bullet points at the top of this article.
Fuel? Check. Oxygen? Check. Do you need a light?
Good evening all and I hope your VMS are tuned and your Free memory is abundant!