Server requirements sizing for smaller environments RRS feed

  • General discussion

  • Hello,

    I am Dutch and I usually work with small- to mediumsized businesses. When I talk about companies of this size, I'm talking about 25-500 people. 500 can even start to be considered large for me.

    Lately I see people, and Microsoft, oversizing their servers tremendously. For example, Microsoft's official minimum hardware requirements for OCS R2 Mediation server is: 2-way or 4-way quadcore 2.0+ GHz with 8GB of RAM. (source: http://technet.microsoft.com/en-us/library/dd572215(office.13).aspx)

    Let's take a look at our company; we have 40 users that all want to use OCS connected to the PSTN. So we have installed OCS R2 Standard with a Mediation server, both on seperate servers. We also are planning to install CWA for the Confernce Attendant. According to Microsoft, all these roles (except for CWA) have to be installed on seperate hardware (non-virtualized) machines. These machines all have to have 8GB of RAM and at least 8 cores. We also want to run Exchange 2007 SP1 with UM, which requires around the same hardware.

    As you can imagine, it's fairly impossible for a small company like ours to buy four of these machines, just to run Microsoft's UC solution. And if we did do so, we would have hugely oversized our system, as 40 people would never make these systems get on their knees. They'd be picking their nose into eternity.

    So as a test, I have set up all servers on óne ESX machine (2x quad 2.5GHz, 18GB RAM) and even combined OCS R2 Standard and Communicator Web Access on one Windows server (with 2 seperate IIS Virtual Servers). This performs perfectly in the test environment, though the test haven't been done by more than 3 people yet. As we only have 40 users, I don't really see many issues here though.

    The goal of this topic is trying to create some awareness of how much oversizing happens. I see it a lot there in The Netherlands, also with other vendors than Microsoft. I have seen companies of 400 users working with Cisco CallManager environments large enough to support at least 5000 users. This is purely a waste of money and powerconsumption.

    I would just like to see that Microsoft adapts a bit to markets like the Dutch one, where companies with thousands of people are relatively unique. Most companies have below 500 people.

    Thanks for your time,
    Ruud van Strijp
    Ruud van Strijp - Student, doing Network Infrastructure Design in the Netherlands. MCSE: 70-270, 70-284, 70-290, 70-291, 70-294, 70-297. Cisco: CCNA, CCDA, CCNP, CCDP.
    Thursday, July 2, 2009 8:51 AM

All replies

  • Hi Ruud,

    We are a Belgian small company with 32 users, and we are running on OCS since the R1 version came out.  I understand your fears about the hardware.  We also virtualise everything OCS (except for the Mediation Server) and did not have any problems.  In fact our OCS 2007 R1 Std Server just had one processor and somewhat like 1 GB of RAM of which it used even less.  We didn't run into any performance issues.

    We recently transitioned to R2 on Win2008 and I noticed the footprint of OCS has gotten a little larger, but looking at the server I guess most of it can be attributed to Windows 2008 itself, and I have the impression that more memory is being cached on Win 2008.   As a result your memory use on the ESX host system will be larger for R2 than R1.  Currently our R2 standard system for 32 users has 1,5GB of committed ESX HOST memory, and uses about 280 Mhz on our Xeon 2.4 Ghz processors.  So in short:  you can run OCS for a small company with a lot less than what Microsoft recommends.  That is the good news, so I would not worry about OCS for small companies.  Actually we were very impressed by the OCS capabilities and performance versus the footprint needed for it.

    To be honest I am worried about a different evolution that I am noticing in the Microsoft world:  the fact that less and less server roles can be combined on single Windows server installation.  Hence probably also the growth of tools like VMWare. 

    Exchange cannot run on a domain controller, Sharepoint cannot be collocated on a domain controller (or at least it is not recommended and need some special attention).  Sharepoint uses its own security plugin in IIS so that virtually no other site or web driven program can run on the same machine.  OCS CWA apparantly uses yet a different security system and hence cannot be collocated with Exchange Web Acces, ... etc.. etc... 

    For some of these roles it makes sense not to collocate them (e.g. AD and Exchange), but I hate it when MS is diverting from their own security systems in IIS and hence breaking other web sites or reducing the options for collocation.  When we set up our environment we really needed some puzzling to optimize the number of machines.  Fortunately we have virtualisation, but each Windows server system you set up also needs to be maintained, backuped, and creates memory overhead (not to mention license costs).

    So, please Microsoft, at least enable OCS CWA and Exchange OWA to run together on one machine. :-)


    Thursday, July 2, 2009 9:38 AM
  • Where is Microsoft response on this?

    To only document supported hardware for very large scale solutsions (e.g. 100,000 endpoints) is not suitable. Microsoft need to have a look at some of their competitors documentation and supported Bill of Material documentation.

    For example, there is conflicting information on mediation server hardware in the Microsoft documentation:
    the below states the MINIMUM hardware requiyurements for a mediation server, (but does not state how many ports it can support - why?)

    While the below URL from the planning guide, documents different specs for the mediation server which are LOWER than the "MINIMUM" specifications (e.g. documents 2 x dual core processes, while min spec documents 2 x quad core and documents only 4GB of RAM),

    What we want is supported, tested and documented hardware for small solutions.
    e.g. 100-500 users, 30/60 PSTN ports.

    These companies still need resilience.
    e.g. a 60 port PSTN system split across two mediation servers and two low end VoIP gateways for some hardware resilience?

    A 30 port mediation server I am sure might be fine on a low end server, such as a 2GB core duo 2+Ghz , but I have not tested it, Microsoft should.

    Microsoft please give us some feedback.

    Tuesday, September 22, 2009 3:16 PM
  • I don't think you'll see much guidance directly from Microsoft about this because they can only support what they've tested, but I can at least share my experience with what has worked well. You can pretty much take the requirements in half for a smaller deployment and be fairly successful. I've also seen some people virtualize roles like the FE and Mediation and never complain about quality, but it all depends on your usage scenario is.

    I can say that for 500 users on OCS for IM, presence, web and A/V conferencing + 30 on Enterprise Voice:

    SE FE + CWA, Edge and Mediation all using dual core 2 GHz, 4 GB RAM, RAID 1 mirror of 10k RPM disks
    Hyper-V Monitoring/Archiving + SQL using dual core 2 GHz, 2 GB RAM, .VHDs all off the same RAID 10 set of disks. 

    has performed admirably in a pinch over the last year. That's not to say it's going to work great you, but for this particular user base it's been just fine. Everyone up on IM/presence all the time and web conferencing getting pretty constant usage. 3+ party A/V not leveraged that often which is where the high hardware requirements really become helpful.
    Tuesday, September 22, 2009 7:47 PM